http://www.mindat.org/msgboard-67.html Thu, 23 May 2013 00:15:33 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,67,278921,278921#msg-278921 http://www.mindat.org/forum.php?read,67,278921,278921#msg-278921 Best Minerals and here for Tourmaline group minerals, here for Chromium-dravite, here for Chromo-alumino-povondraite, here for Dravite, here for Elbaite, Afghanistan to Nigeria, here for Elbaite, Pakistan to Zambia here for Feruvite, here for Fluor Buergerite here for Fluor-dravite, here for Fluor-elbaite, here for Fluor-feruvite, here for Fluor-liddicoatite, here for Fluor-schorl, here for Foitite, here for Liddicoatite, here for Luinaite-(OH), here for Magnesiofoitite, here for Olenite, here for Oxy-dravite, here for Oxy-rossmanite, here for Oxy-schorl, here for Povondraite, here for Rossmanite, here for Schorl, here for Tsilaisite and here for Vanadium-dravite. Click here for Best Minerals T and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Buergerite: Currently not a recognized species; the original buergerite has been renamed fluor-buergerite (Henry et al., 2011).
The reason this name is maintained here in the tourmaline group is because of the very many specimens in collections around the world. It will take generations for most of the labels to be corrected.



Click here to view Best Minerals and here for Tourmaline group minerals, here for Chromium-dravite, here for Chromo-alumino-povondraite, here for Dravite, here for Elbaite, Afghanistan to Nigeria, here for Elbaite, Pakistan to Zambia here for Feruvite, here for Fluor Buergerite here for Fluor-dravite, here for Fluor-elbaite, here for Fluor-feruvite, here for Fluor-liddicoatite, here for Fluor-schorl, here for Foitite, here for Liddicoatite, here for Luinaite-(OH), here for Magnesiofoitite, here for Olenite, here for Oxy-dravite, here for Oxy-rossmanite, here for Oxy-schorl, here for Povondraite, here for Rossmanite, here for Schorl, here for Tsilaisite and here for Vanadium-dravite. Click here for Best Minerals T and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Wed, 12 Dec 2012 12:31:18 +0000 http://www.mindat.org/forum.php?read,67,260515,260515#msg-260515 http://www.mindat.org/forum.php?read,67,260515,260515#msg-260515 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Benitoite hexagonal
BaTi(Si₃O⁹)

Benitoite on Natrolite ~4cm Dallas Gem Mine, San Benito Co., California	©

Benitoite is a fairly uncommon mineral and Mindat lists about 20 localities, only one of which is of considerable interest to collectors. As you look at the images presented below, it will become clear why this is so. The hand book of minerals lists 6 cm as the largest size for Benitoite crystals, but probably at least one exceeds that size. The best locality for Benitoite by far is the the Gem Mine in San Benito County, California, USA. It has produced tens of thousands of Benitoite specimens over the last 100 years.


Benitoite
Japan
Honshu Island, Chubu Region, Niigata Prefecture, Itoigawa City, Hashidate

Benitoite 2mm xl group	©

Benitoite
Japan
Honshu Island, Chubu Region, Niigata Prefecture, Itoigawa City, Hashidate, Kinzandani

Benitoite 2.5cm tall	© Y.Okazaki

Benitoite 1.1cm wide	© A&M

.

Benitoite 8.6mm wide	© A&M

Benitoite FOV 4mm.	© T. Mine

Benitoite
Japan
Honshu Island, Chubu Region, Niigata Prefecture, Itoigawa City, Ohmi, Ohmi river (Ohmi-gawa)

Benitoite FOV 5mm	© Hiroaki TANO

Benitoite
USA
Arkansas, Hot Spring Co., Magnet Cove, Jones Mill Quarry (Martin Marietta Quarry; Highway 51 Quarry; Mid-State Quarry)

.2mm Benitoite xls on Orthoclase	© C. Stefano '08

Benitoite
USA
California, San Benito Co., Diablo Range, New Idria District, Picacho Peak, Clear Creek area, Hernandez, Clear Creek, Mina Numero Uno

5mm Benitoite crystal on matrix	© Trinity Mineral Co.

Benitoite xls ~3mm wide	© Minresco

Benitoite
USA
California, San Benito Co., Diablo Range, New Idria District, San Benito River headwaters area, Dallas Gem Mine area, Dallas Gem Mine (Benitoite Mine; Benitoite Gem Mine; Gem Mine)

Benitoite, Neptunite & Joaquinite 3.1cm	©

Benitoite & Neptunite 5.3cm wide	©

Benitoite 4.6cm wide	©

Benitoite 2cm tall	©

Benitoite 5.5cm tall	©

8mm Benitoite on Natrolite	©

Benitoite & Neptunite 5.1cm wide	©

Benitoite & Neptunite 4cm wide	©

Benitoite 1.7cm wide	©

Benitoite & Aegirine 6.6cm wide	©

Benitoite 6.2 cm wide	©

Benitoite & Neptunite 5.1cm wide 10cm wide	©

Benitoite 18cm wide

Benitoite & Neptunite 14.7cm wide	© Rob Lavinsky

Benitoite 1.7cm wide	© 1995-2001 Trinity Mineral Co.

Benitoite 2cm wide	© 2001 John H. Betts

Benitoite & Neptunite 9cm wide	© Rob Lavinsky

Benitoite & Neptunite 10.6cm wide	© fabreminerals.com

Benitoite on Natrolite 5.3cm wide	© fabreminerals.com

Benitoite 6.2cm wide	© Collectors Edge

Benitoite on Natrolite 7.5cm wide	© Rob Lavinsky

Benitoite 2.4cm wide	© Marin Mineral

Benitoite & Neptunite 8cm wide	© FRANCO LAZZARI

Benitoite 5.5cm wide	© Dr. Perry Silver

Benitoite & Neptunite 7.6cm wide	© Weinrich Minerals, Inc.

Benitoite & Neptunite 4.2cm wide	© Marek Patúš

Benitoite 6.7cm wide	© Rob Lavinsky

Benitoite ~3cm tall	© Dr. Perry Silver

Benitoite 4cm wide	©

Benitoite on Natrolite 2.9cm wide	© Weinrich

Benitoite & Neptunite 9cm wide	© luigi chiappino

Benitoite & Neptunite FOV 6.5mm	© G. Bernadi

Benitoite on Natrolite 3.1cm tall	©

Benitoite & Neptunite 3.8cm wide	©

Benitoite & Neptunite 5.7cm wide	©

Here is an article written about the Gem by John Veevaert about the Gem Mine that was published in a recent magazine that he has give Mindat permission to reproduce here.

Benitoite – almost every mineral collector desires to have a specimen of this unique blue mineral in their collection. Aside from a few small nearby deposits only the Benitoite Gem mine has commercially produced benitoite in gem quality and specimens of stunning beauty. Since its discovery in 1907 literally tens of thousands of specimens of benitoite and neptunite have been produced. It is a slow and involved process to remove the encasing natrolite with various chemicals but the effort is worth it to preserve the mineral heritage from one of the most unique mineral deposits in the world. The State of California recognized the significance of this distinctive mineral by declaring it to be the Official State Gemstone of California. On October 1, 1985 in Sacramento, California, the State legislature passed Assembly Bill no 2357. The text was simple but it was everything that everyone who knew anything about benitoite had ever hoped for. Section 425.3 is added to the Government code to read: ”Benitoite is the official state gemstone of California”.


LOCATION
The Benitoite Gem mine, formerly known as the Dallas Gem mine, is situated near the southern tip of San Benito County about 30 km to the north and west of Coalinga, California. The town of King City lies about 45 km to the west of the mine. In a broader sense the mine lies about half way between San Francisco and Los Angeles. When people think about California they tend to think of lots of people and endless beaches. This section of California is considered remote by just about any standard imaginable. Few roads and amenities, that most people are used to, can be found for 30 km in any direction. The only way to get near the mine, other than a privately owned chip sealed road, is via dirt road and most of it is quite bumpy and requires several stream crossings. Travel in the winter time is nearly impossible due to snow or very slick, muddy roads. The mine is set jut upslope of the San Benito River at an altitude of 1,380 meters.

The coastal mountains between San Francisco and Los Angeles are expansive and, even today, for the most part, empty of any human development other than ranches and a few small towns and roads which transect them. Imagine the difficulty in accessing this region in 1907, the year benitoite was discovered, when there were no roads and the only means of moving through the area was on foot. The vegetation in the area consists of very thick chaparral that is seemingly impossible to walk through yet that was the task set in front of James Couch as he left Coalinga to prospect the area in southern San Benito County for new mercury deposits in early February.

HISTORY OF THE DEPOSIT
James Marshall Couch had been grub staked by Roderick Dallas and Thomas Sanders with $50 worth of supplies and a horse. It was mid-winter when Couch set out so there was likely some cold weather to contend with as he made his way into the headwaters of the San Benito River looking for traces of minerals eroding out of the adjacent hills. It is reported in several sources that he found a forested glade along the small river and made camp after having been prospecting for several weeks. This offered him a flat place with grass for his horse to feed on and plenty of firewood for himself to keep warm during the long cold nights.

Accounts of the discovery report that on February 22, 1907 Couch climbed the hill across from his camp to look for possible outcrops to investigate. On his way up the slope he stumbled on a small area literally littered with myriad small dark blue crystals. He initially suspected the crystals to be diamonds or sapphires owing to the blue color and set about to collect a small hoard then raced back to Coalinga to announce his discovery. It is possible that the Native Americans who inhabited this region may have seen this deposit at some point in the distant past on a hunting trip but as far as Couch could tell no one had ever been to this spot before. Credit for the discovery was taken by other people, primarily Roderick Dallas and another fellow by the name of Leland Hawkins but sifting through the historical records suggests that Couch was the sole discoverer of the deposit. Imagine this outcrop weathering for millennia with no one knowing of its existence and then imagine being the first person to have ever seen this rich blue mineral laying in abundance on the ground…

The Gem Mine area in 1909	©

The Gem Mine in 1908	©

It did not take long for the area to be legally claimed and mining to commence. (The claim was given the name of Dallas Gem mine in recognition of the financial backing provided by Dallas for the operation.) Still, none of the characters who were involved knew what it was that they were mining. Speculation centered on the crystals being sapphire or spinel or even some form of volcanic glass. Later in 1907 a small group of specimens found their way to Dr. George Louderback who was professor of mineralogy at the University of California, Berkeley. Louderback quickly recognized that this blue mineral was new to science. He also thought that the accompanying dark black mineral, associated with the blue mineral, was also new to science. He set out to publish a preliminary note in July 1907 on the new species and tentatively called the blue mineral benitoite named after San Benito County and the San Benito River. He suggested that the black mineral be named carlosite after the nearby San Carlos Peak. Later in 1907 Louderback determined that carlosite was in fact neptunite – a mineral which had been discovered in 1893 in Greenland.

After securing more specimens and having a chance to actually go to the mine site Louderback commenced to formerly describe the new mineral benitoite. Many people consider this one of the finest descriptions of a new mineral species ever written. It was published in 1909 with the chemical analyses being completed by Walter Blasedale. All of the hand-colored copies were quickly dispersed to universities and mineralogists around the globe.

Initially all of the recovery of benitoite consisted of breaking open the encasing natrolite by sledge to find the gem nodules. Perhaps hundreds or even thousands of stunning specimens were lost through this method.

Benitoite ore consisting mostly of white natrolite.	©

It did not take long, however, for the miners to learn that natrolite was soluble in various acids. It must have been quite a scene to see hundreds of kilos of natrolite veins in acid to expose the enclosed benitoite crystals. Today using acids and other chemicals are used to prepare specimens and recover gem rough. However, greater care and effort are taken to clean aesthetic specimens by trimming excess matrix and protecting some of the natrolite which provides a striking contrast between both benitoite and neptunite.

Specimen before cleaning	©

During cleaning	©

During cleaning	©

During cleaning	©

During cleaning	©

Almost finished	©

Finished cleaning	©

The Dallas operation of the mine went on until 1910. At that time operations were ceased and the mine abandoned. Dallas, however, maintained the assessment work on the claim and was able to patent the ground maintaining permanent control over the deposit. From then until the 1960’s the Dallas family leased to the property to various operators who recovered specimens and gem rough. Perhaps most noteworthy of this group were Pete Bancroft and Ed Swoboda who visited the mine several times between 1935 and 1938 collecting thousands of specimens. In the 1930s it was still no small task to get this remote location. In 1935 they set out to visit the deposit after having been given directions to the locality from their high school teacher, Frank Gulick, who had actively collected at the deposit the year before in 1934.

Pete Bancroft at the Gem Mine in 1938	©

From the 1940s until 1967 the deposit was leased by several people with various levels of production. Most notably Miller Hotchkiss in 1952, Clarence Cole from 1953 to 1967, and Josephine Scripps, sub-leased from Cole, in 1966. Their efforts were modest in terms of overall production.

In 1967 Elvis “Buzz” Gray and Bill Forrest leased the property. They were experienced operators and set about to rehab the mine site and develop a logical plan for the deposit. Their efforts produced countless thousands of good specimens and considerable gem rough. It was also their effort to promote benitoite as a gemstone that raised the awareness such that California designated the mineral as the official gemstone of California in 1985. They bought the mine in 1987 from the Dallas family. They continued to operate the mine from 1967 until 2000. Frequently seen at the mine was Fresno County Sheriff’s Deputy Bob Kahl. Bob was there to lend some security to Bill and Buzz and also to help out as needed.

The Gem Mine as it was near the end of Elvis "Buz" Grays and Bill Forest's tenure.	©

In 2001 Gray and Forrest sold the mine to Collector’s Edge of Denver, Colorado. Bryan Lees, the principal owner of the company, oversaw a complete and thorough mining of the remaining deposit. He exposed the original vein system and found that it had been completely worked out. His operation also ran the entire dump material, through a custom jig system to separate gem rough. He then set out to process the colluvial and eluvial material that had eroded from the original deposit over the millennia. A conveyor belt also carried larger rocks off and each, while wet, were visually inspected for specimen potential. His operation produced many tons of specimen grade material and thousands of carats of gem rough. The mine site was completely rehabilitated according to Surface Mining and Reclamation Act standards in 2004.

The Gem Mine in 2006	©

The Gem Mine in 2007?	©

Bryan Lees sold the mine to Dave Schreiner of Coalinga in 2004. Dave was determined to create a fee dig operation there but has been hindered with environmental regulations set by the Environmental Protection Agency and Bureau of Land Management due to the vast amount of naturally occurring asbestos. Reckless All-Terrain Vehicles and motorcycles over the last 50 years have created enormous erosional problems as well so the agencies established a closure of the area to all vehicular traffic allowing only private property owners and valid claim holders access. For the past several years Dave was trucking material from the mine to the Los Gatos Community park just outside of Coalinga and allowing people to screen the material for gem rough and specimen material. The opportunity to find specimen material or gem rough does not currently exist unless groups access the mine via a private chip sealed road. Even then the previous mining efforts by Collector’s Edge left very little material behind.

In 2008 John Veevaert of Weaverville, California (author) and Steve Perry of Davis, California negotiated the purchased the entire nine plus tons of inventory of benitoite specimens, partially processed and unprocessed mine run material from Collector’s Edge. We have made some of this material available for collectors to purchase and try their hand at cleaning their own specimens. We are also processing a lot of the material for specimens and minor gem rough.

The vein systems at the Benitoite Gem mine have been exhausted. Collector’s Edge removed all overlying colluvium and bedrock to expose what was left of the vein system. Any mineralized segments of original vein remaining at that time were removed. All of the colluvial material was processed twice to look for gem rough and specimen potential. After completion of that activity the mine site was reclaimed and recontoured.

Despite the effective mining techniques used by Collector’s Edge a minor amount of productive material still remains. The mud adhering to much of the material is tenacious and nearly impossible to remove without repeated wetting and abrasion. This masking mud allowed considerable material to pass through the washing system undetected and was eventually used in the reclamation work. Hence, some of this mineralized material will continue to be found through the action of rain and intense field collector interest. The mine, however, will never again produce at a commercial scale.

THE GEOLOGY OF THE AREA
The Benitoite Gem mine is located in the New Idria district situated in the southern end of the Diablo Range. The district has been prospected since the early 1850s for gold, mercury, chromium, asbestos and mineral specimens. The district is found within a large body of serpentinite which was tectonically emplaced into surrounding sedimentary and metamorphic rocks in the Jurassic. A subsequent plate collision put downward pressure on the serpentinite. However, being of a lighter density portions separated and migrated upward the overlying layers of rock. This established the foundation of a setting where these portions of serpentinite would experience low temperature and high pressure metamorphism – that of a blue schist facies. During the mid Miocene the region was intruded by small igneous bodies – primarily of syentic composition. This produced numerous calc-silicate vein systems throughout the district. It was one of these systems, altering the blue schist rock, that deposited the mineral resources found at the Benitoite Gem mine.

ORIGIN AND STYLE OF MINERALIZATION
The elements that comprise benitoite are thought to have been mobilized from the host rock and deposited in a late stage cooling of hydrothermal fluids in calc-silicate veins fracturing the wall rock of blue schist blocks. Other nearby benitoite deposits have a similar setting so this bears out the hypothesis. Previous geologic investigations have suggested that the benitoite mineralization was subsequent to the formation of the blueschist. Their analysis place the age of the blueschist at between 100 and 160 million years of age and the benitoite present in the cross cutting calc silicate veins at approximately 12 million years. All benitoite in situ at the Benitoite Gem mine is confined to blueschist blocks altered by hydrothermal veins. The last phase of mineralization was confined to a pulse of natrolite that set into the vein system. The vein filling natrolite is found to encase most, but not all, of the minerals deposited in the earlier phases. The upper zone of the Benitoite Gem mine has a large concentration of albite veins and is void of natrolite. It is in this upper zone that rich, deep blue and lustrous crystals of benitoite were found commingled with milky white albite.

Most of the natrolite veins are less than 2 cm thick. The minerals of interest at the mine are confined to the vein systems and frequently are attached to both vein walls. This creates an obvious problem during specimen preparation as one side of the vein has to be mechanically removed to offer a chance at producing a specimen.

Though the lower level portions of the vein system were typically filled with natrolite some pockets were left intact. These pockets typically display blocky natrolite crystals and in some cases neptunite and benitoite crystals are still exposed. The size of these pockets is generally quite small rarely exceeding 2 cm in size. As mentioned earlier, the upper zone is void of natrolite. All minerals found in that zone tend to be only hidden by clay minerals which can be easily removed with water. Pocket zones were still not large and mineralization was much more scattered but the crystal quality of benitoite and joaquinite is much higher not having been subjected to the natrolite bearing solutions.

MINERALS FROM THE BENITOITE GEM MINE.

BENITOITE (TL)
Benitoite is the primary mineral of interest from this deposit. The chemical formula for benitoite is BaTiSi3O9. It is a ring silicate and crystallizes in the hexagonal crystal system. Early in the theoretical development of crystallography it was hypothesized that there was a class of the hexagonal system that would produce trigonally shaped crystals. The discovery of benitoite provided the mineral world with the first species known to crystallize in the ditrigonal-dipyramidal class of the hexagonal crystal system. This class is referred to as the “Benitoite Type” in Dana. Twinning of benitoite occurs on the c-axis (0001) with two crystals rotated 60 degrees. Equidimensional twinned crystals are referred to as a "Star of David" owing to their perfect six sided star. Twinning is only found in benitoite crystals included with crossite. Complete crystals of this form are very rare.

Benitoite twined "stars of David" maximum size 3.3cm wide	©

Benitoite is found in two classes at the mine – a euhedral crystals heavily included with amphibole minerals such as crossite or actinolite and as crystals attached to the vein walls. It is in the latter areas that gem benitoite has been recovered. The crystal faces of benitoite were selectively etched during the natrolite phase of mineralization. Rare examples of crystals exists with all brilliantly lustrous faces occurring but in most benitoite the c face and prism faces retained their luster while the pyramidal faces became duller due to etching during the natrolite phase.

Other principal minerals found in the vein system at the mine include neptunite, the joaquinite series, frensoite, silica pseudomorphs after serandite, apatite, jonesite and various sulfides of copper including chalcocite, djurleite and covellite. The sequence of minerals has been determined to be: albite, apatite, silica pseudomorphs, neptunite, copper sulfides, benitoite, joaquinite series, jonesite and natrolite which filled most of the vein system.

Pervious literature suggested that jonesite was not found in situ with benitoite. The author has several specimens and knows of others that show a commingling of benitoite and jonesite together. So their emplacement in the vein system may have been concurrent.

Not all benitoite is created equally. While the more popular color is a rich sapphire blue with a hint of violet, benitoite comes in clear, white, pink, reddish brown or greenish-gray color as well. The origin of the color of benitoite has not been completely determined as of yet. It does contain traces of iron (Fe), hence it has been proposed that color may be due to the Fe2+ - Ti4+ or the Fe2+ - Fe3+ intervalance charge transfer. Joan Mamarella (personal communication 1997) suggests in her thesis that the blue color is derived from the titanium in the blue portions of the crystals being paramagnetic while the titanium in the white portions are diamagnetic.

Benitoite is very strongly dichroic such that when shifted in the proper orientation it looks either colorless, blue, or rich violet-blue in color. Benitoite has a high birefringence - higher than that of diamond. Hence, cut stones come alive with fire from refracted light. The blue color of benitoite is not affected by any treatment such as heat or irradiation. The colorless sections of a benitoite crystal have been changed to orange when heated (Bill Forrest personal communication 2002).

Benitoite is also found, frequently, as gray to greenish colored crystals with very heavy inclusions of the amphibole crossite. Some crystals of benitoite appear red to dark maroon due to inclusions of minute neptunite crystals. The vast majority of crossite included are floaters with complete terminations on both ends.

Benitoite is strongly reactive under a short wave ultraviolet (SW UV) light source. It fluoresces a very bright, opaque, sky blue color. The fluorescence seems to be stronger in crystals with crossite inclusions than crystals of gem quality. Some crystals fluoresce a dull reddish orange color under Long Wave Ultraviolet light. The strong reaction under SW UV light is a very useful tool for locating specimens at the mine and for prospecting.

The primary use of benitoite is for mineral collectors and use as an ornamental gemstone. Though not suitable for use in rings due to its hardness of 6.5 it is dazzling in pendants, earrings and necklaces. The vast majority of finished gems are under ½ carat weight. Gems over 1 carat are rare and gems over 2 carats are considered very rare. The largest known piece of rough recovered was a 34 carat piece found by the current owner Dave Schreiner shortly after he acquired the mine from Collector’s Edge, Inc. It produced a finished stone of over 8 carats and several smaller stones. The largest known faceted benitoite is owned by Mike Scott and is a 15.42 ct stone.

The prices of finished gemstones have skyrocketed in recent years. As a gem benitoite is orders of magnitude scarcer than diamonds, emeralds and rubies. High quality finished stones of one carat with good clarity and color will fetch $3,000 or more. Stones of two carats can bring $8,000-$10,000. It will continue to appreciate in value in future as the supply is limited and future commercial production will not happen.

Most new minerals discovered in the last 100 years have been as a result of some unusual diffraction pattern in an X-Ray analysis or as some microscopic crystals that could only be appreciated under a scanning electron microscope. Benitoite caused an immediate sensation with its large well-formed crystals accompanied by equally striking crystals of neptunite and joaquinite. There have been few occasions in the history of mineral discoveries when a new species was found in such magnificent crystals.

NEPTUNITE
The Benitoite Gem mine has produced the world’s finest known crystals of neptunite. It’s chemical formula is: KNa2Li(Fe2+, Mn2+)2Ti2Si8O24. The principle habit is prismatic though some stubby crystals are known. At a macro scale neptunite appears to be jet black in color. It is actually a deep red color which is seen at certain angles in large crystals or in micro crystals where light can pass through it. Neptunite two types of twins. The most common is a twin on (301). The rarest twin is that found on Miller Indices (001). To my knowledge there are no more than eight or nine of these are known.

JOAQUINITE – Ce (TL)
Joaquinite was first discovered at the Benitoite Gem mine. It’s chemical formula ls: NaFeBa2Ce2(Ti,Nb)2[Si4O12]2O2(OH,F)•(H2O). It is by far the most complex mineral found in terms of chemistry. Two other species have been delineated which include strontiojoaquinite and barrio-orthojoaquinite. In the latter two, niobium and cerium are absent. The ratios of strontium to barium determine which species it is. Most of the joaquinite found at the deposit are 3mm or less in size and have a honey to cinnamon color. Joaquinite was originally thought to crystallize in the orthorhombic system. However, later work determined that twinning on 001 created the orthorhombic crystal shape.

JONESITE (TL)
Jonesite was discovered in 1957 by Francis Jones. It was later described in 1977 as a new species. It is by far the rarest mineral found at the deposit. It’s formula is: Ba4(K,Na)2[Ti4Al2Si10O36]*6H2O . It forms small colorless crystals up to 3mm in length but usually far smaller as single bladed crystals or as sprays. The crystals form in the orthorhombic crystal system. For some time it was thought jonesite did not form with benitoite but specimens in the author’s collection readily dispute this notion.

NATROLITE
Natrolite is comprised of: Na2Al2Si3O10 • 2H2O. It is ubiquitous throughout much of the deposit. It was deposited in the last pulse of mineralization in the vein system and is only rarely encountered in crystals. Where the veins did not entirely fill with natrolite stubby, prismatic crystals are found. The crystals are invariably milky white and opaque. Much of the well crystallized natrolite in collections labeled as coming from the Benitoite Gem mine is in fact from several other nearby deposits.

OTHER MINERALS
In addition to the above species the most commonly encountered include the copper sulfides djurleite and chalcocite. Other noteable species include: apatite, albite, manganese oxides, silica pseudomorphs presumed to be after serandite and analcime. Several oddities are also known including boatite and a unique specimen of wire silver exsolved from a djurleite crystal.

SPECIMENS
Most of the early efforts to recover benitoite was done mechanically and was focused primarily on the recovery of gem rough. This resulted in countless thousands of specimens that were battered and not suitable for collections. Once the use of acids was employed to remove the natrolite the quality of specimens increased exponentially. It is hard to rank the finest specimens but two specimens in the LA County Museum are considered to be among the best – a large 3 cm triply terminated crystal and a fabulous ring of adjoined benitoite crystals. A smaller specimen in the author’s personal collection is considered one of the finest with the three species – benitoite, neptunite and joaquinite arranged in an aesthetic position. It has been dubbed the “sushi plate”.

So, what does it take to get a cleaned specimen of benitoite and/or neptunite? Attractive specimens of this beautiful mineral assemblage just don't happen - they are literally crafted! The process involves several steps which are all time consuming and require a bit of artistic aptitude. One thing to keep in mind during the process is that removing matrix is a one way procedure. Once it is removed it cannot be put back. Too much removal is as detrimental to the finished specimen as leaving too much.

Several steps applying an etch inhibitor, soaking in acid and rinsing are necessary to remove enough of the natrolite so as to end up with an aesthetic specimen. More information on how to clean specimens from this deposit can be found at benitoite.com.

To be done right an average specimen requires no less than 10-20 days of attention. Many require a great deal more. In the past I have personally spent over a month’s time on one rock! Doing the work with batches of specimens is the only way this becomes feasible and economical. It is no wonder that prices for the top levels specimens are what they are for this rare mineral given the amount of time it takes to make these specimens look the way they do. The labor costs of cleaning specimens from the Benitoite Gem mine correctly are rarely recovered...

A final word here on benitoite from the Benitoite Gem Mine. I am guessing that 98% of all benitoite crystals have a matted luster. The pinacoid and prism faces will be lustrous 10 times out of 10. The pyramidal faces, however, will not. That is just the way Mother Nature created these things. Some crystals will be lustrous on all faces and those specimens are rare. The other thing to remember is when something has sat around for millions of years some fracturing is likely to occur. The vast majority benitoite crystals were fractured though eons of natural processes. When you are finished etching the specimens with benitoite you will likely see the fractures as the specimen dries. There is nothing you can do to change this fact, so accept it. I etch hundreds of specimens a year and find the severe fracturing probably 80% of the time and put most of those specimens in the wholesale flats. That is why the high quality benitoite specimens command high prices. They are, unfortunately, the exception to the rule.
[John Veevaert 2011]
The original article was published by Minerals, Issue 3, 2011: [www.mindat.org]

The first edition of this article was completed on 9 August 21123.





Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Fri, 11 May 2012 18:25:28 +0000 http://www.mindat.org/forum.php?read,67,253056,253056#msg-253056 http://www.mindat.org/forum.php?read,67,253056,253056#msg-253056 Rock Currier Best Minerals B Sun, 18 Nov 2012 09:54:32 +0000 http://www.mindat.org/forum.php?read,67,226329,226329#msg-226329 http://www.mindat.org/forum.php?read,67,226329,226329#msg-226329

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Click here for a list of articles that are not under construction but have had at least their first drafts finished.

This article is a place holder and needs someone to take it in hand and finish the first draft. If you would like to take this article in hand, leave a reply message below or contact Rock Currier via private message by clicking on the PM button next to my name at the top of the article.



This Article is Under Construction

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Place holder

Rick Dalrymple has expressed interest in working on this article












Click here to view Best Minerals B, click here to view and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Sun, 27 Jan 2013 14:10:42 +0000 http://www.mindat.org/forum.php?read,67,221776,221776#msg-221776 http://www.mindat.org/forum.php?read,67,221776,221776#msg-221776 Beryl, here for Beryl var: Emerald, here for Beryl var: Aquamarine, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.

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Beryl var: Goshenite
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

Goshenite, Albite and Muscovite on matrix. 8,3x5,6x5,5cm. Mt Xuebaoding, China	© Jiangbin

Introduction:


Goshenite
Brazil
Minas gerais, Doce valley

Goshenite 3,2cm	© Weinrich Minerals

Goshenite 5,4cm	© Rob Lavinsky

Info:

Work in progress]]> Harjo Neutkens Best Minerals B Wed, 27 Apr 2011 14:03:41 +0000 http://www.mindat.org/forum.php?read,67,221774,221774#msg-221774 http://www.mindat.org/forum.php?read,67,221774,221774#msg-221774 Beryl, here for Beryl var: Emerald, here for Beryl var: Red Beryl, here for Beryl var: Aquamarine, here for Beryl var: Morganite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Heliodor
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

Heliodor, Murzinka, Russia 3,1cm	©

Introduction:


Heliodor
Afghanistan
Konar Province

Heliodor 3,6cm	© Eric Graff

Heliodor 4cm	© D&D Weinrich

Nuristan province sensu strictu became officially recognised in 2001 (wikipedia) or 2004 (statoids.com), but was already known for 10 years. It was formed from the northern parts of Laghman Province and Konar (Kunar) Province.
Note, however, that "Nuristan" is also the traditional name for the region that encompasses these three current provinces (i.e., NE Afghanistan) and the name is still often used in that fashion.
Konar Province covers most of the Afghan part of the Konar valley, and most of the valleys of its confluents. Only a small part of the lower valley, a few kilometers upstream of its confluence with the Kabul river near Jalalabad, belongs to Nangarhar Province. Depending on which confluents are considered an integral part of the valley, the area referred to as "Konar Valley" may cover anything between about two thirds and all of Konar Province, making it not only a rather vague but also an ill-defined locality description. Therefore, photos of specimens labelled as coming from Konar Valley should be placed under Konar Province.

Possibly/probably, many Heliodor specimens from Konar province are irradiated Aquamarine crystals.


Work in progress]]> Harjo Neutkens Best Minerals B Wed, 27 Apr 2011 13:50:35 +0000 http://www.mindat.org/forum.php?read,67,221770,221770#msg-221770 http://www.mindat.org/forum.php?read,67,221770,221770#msg-221770 Beryl, here for Beryl var: Emerald, here for Beryl var: Red Beryl, here for Beryl var: Aquamarine, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles

Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Morganite
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

Morganite with Quartz on Cleavelandite, 19,2cm. Laghman Provonce, Afghanistan	© www.exceptionalminerals.com

Introduction:


Morganite
Afghanistan
Konar Province, Chapa Dara District, Dara-i-Perch

Specimen 11,9cm	© www.exceptionalminerals.com

Morganite 5,1cm	© Rob Lavinsky

Be-Nb-Ta-Li-rich pegmatites, hosted in a variety of lithologies. There are two types of pegmatites found within the ore field: (1) large albitized microcline pegmatites with beryl, and (2) spodumene-albite pegmatites with complex Li-Be mineralization.

Pech, Peech and Dara-i-Pech (also spelled Darra-i-Pech, Darrah Pech, and sometimes Page) are the same place. "Dara" means "valley", so in English the location name is "Pech Valley". Likewise, specimens labelled as coming from Dara-i-Pech do not necessarily come from this pegmatite field, but may originate from any place in the Pech valley. This area icludes Chapa Dara, Dara-i-Pech, Wata Pur and Asadabad Districts in Konar Province, as well as Wama District in Nuristan Province.
Further note that many Afghanis will still use the name "Nuristan" in a traditional sense, to mean all of northeastern Afghanistan. This traditional meaning of the place name "Nuristan" is not to be confused with the current Nuristan Province, which covers only a portion of "Nuristan" in the traditional sense. Moreover, there also exists a Nuristan District, which covers a minor part of southern Nuristan Province.


Morganite
Afghanistan
Laghman Province

Specimen 8cm	© www.exceptionalminerals.com

Morganite 8cm	© H. Obodda

Nuristan province sensu stricto (http://www.mindat.org/loc-135473.html) became officially recognised in 2001 (wikipedia) or 2004 (statoids.com), but was already known for 10 years. It was formed from the northern parts of Laghman Province and Konar (Kunar) Province.
The capital of the Nuristan Province is Nuristan.
Note, however, that "Nuristan" is also the traditional name for the region that encompasses these three current provinces (i.e., NE Afghanistan) and the name is still often used in that fashion.

Known for very nice pink Morganites with centres of blue Aquamarine.


Work in progress]]> Harjo Neutkens Best Minerals B Wed, 27 Apr 2011 13:35:01 +0000 http://www.mindat.org/forum.php?read,67,221687,221687#msg-221687 http://www.mindat.org/forum.php?read,67,221687,221687#msg-221687 Beryl, here for Beryl var: Emerald, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Aquamarine
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

Aquamarine, 18,3cm tall. Haramosh Mountains, Pakistan	© Rob Lavinsky

Aquamarine derives its name from the Latin name Aqua Marina, meaning "Sea Water", because of it's splendid blue colour.
The colour can come in many shades of blue; light blue, deep blue, green-blue, and many shades in between. The colour is caused by trivalent Iron (Fe³⁺) and/or divalent Iron (Fe²⁺) occupying different positions in the lattice structure.
The habit of Aquamarine varies from needles through elongated prisms to tabular habits. Crystals can be found free-standing in vugs or embedded in host rock, sometimes as parallel grown or radial aggregates.
Aquamarines can be found in pegmatite occurrences, Alpine-type clefts, pneumatolythic occurrences and alluvial gem gravels.
The size of the crystals ranges from micro crystals of less then a mm, up to crystals in excess of 100kg. The largest cut gems weigh over a 1000ct.



Aquamarine
Afghanistan
Konar Province, Chapa Dara District, Dara-i-Pech pegmatite field

Aquamarine, 4cm	© 2002 John H. Betts

Aquamarine 4,4cm	© Russell G. Rizzo

Be-Nb-Ta-Li-rich pegmatites, hosted in a variety of lithologies. There are two types of pegmatites found within the ore field: (1) large albitized microcline pegmatites with beryl, and (2) spodumene-albite pegmatites with complex Li-Be mineralization.

Pech, Peech and Dara-i-Pech (also spelled Darra-i-Pech, Darrah Pech, and sometimes Page) are the same place. "Dara" means "valley", so in English the location name is "Pech Valley". Likewise, specimens labelled as coming from Dara-i-Pech do not necessarily come from this pegmatite field, but may originate from any place in the Pech valley. This area icludes Chapa Dara, Dara-i-Pech, Wata Pur and Asadabad Districts in Konar Province, as well as Wama District in Nuristan Province.
Further note that many Afghanis will still use the name "Nuristan" in a traditional sense, to mean all of northeastern Afghanistan. This traditional meaning of the place name "Nuristan" is not to be confused with the current Nuristan Province, which covers only a portion of "Nuristan" in the traditional sense. Moreover, there also exists a Nuristan District, which covers a minor part of southern Nuristan Province.


Aquamarine
Afghanistan
Laghman Province (Lagman Province; Nuristan)

Aquamarine, 3,7cm	© 2003 John H. Betts

Aquamarine 3,2cm	© 2003 John H. Betts

NOTE: Nuristan province sensu stricto became officially recognised in 2001 (wikipedia) or 2004 (statoids.com), but was already known for 10 years. It was formed from the northern parts of Laghman Province and Konar (Kunar) Province.
The capital of the Nuristan Province is Nuristan.
"Nuristan" is also the traditional name for the region that encompasses these three current provinces (i.e., NE Afghanistan) and the name is still often used in that fashion.


Aquamarine
Argentina
Córdoba, Dumesnil, La Esperanza Quarry

Aquamarine, 3,4cm	© Rob Lavinsky

Aqua, 3,6cm	© Rob Lavinsky

Locality for nice etched Aquamarine crystals.


Aquamarine
Australia
New South Wales, Clive Co., Torrington

Aquamarine, 3,8cm	© www.australiancrystals.com.au

Aquamarine, 3,8cm	© Jon Mommers

There are over 35 Beryl occurrences in Torrington-Emmaville districts of the New England region, and many fine Beryl specimens have been mined since its discovery in the 1890's (whilst prospecting for tin, bismuth and tungsten).
Beryl crystals up to 30cm have been found, sometimes in excellent quality.


Aquamarine
Australia
Northern Territory, Harts Ranges (Hartz Ranges), Harding Springs

Aquamarine, 14cm	© Patrick Gundersen

Aquamarine, 6cm	© Patrick Gundersen

Pegmatite district, with pegmatites originally mined for mica. Beryl crystals over 30cm in length have been reported.


Aquamarine
Austria
Carinthia, Hohe Tauern, Reißeck group, Pusarnitz, Hintereggengraben

Crystals up to 0,5cm	© Rudo

Aquamarine xls 0,5cm	© Rudo

The mountain ridge between Böser Nase and Hochegg in Hintereggengraben which has become famous because of its excellent Sceptre Quartzes is also known as location for nice Aquamarine crystals. The numerous alpine clefts in that region mostly produce Smoky Quartz together with black Tourmaline needles. Sometimes but very rarely a cleft also has some tiny Aquamarine crystals that are often not seen by the collectors.


Aquamarine
Austria
Salzburg, Hohe Tauern Mts, Felben valley, Scheelite deposit, Western ore field

Aquamarine, 3,4cm	© mslama

Aquamarine, 1,97cm	© mslama

Scheelite deposit, currently mined underground. Strikingly deep blue Aquamarines have been found, usually accompanied by Molybdenite and Scheelite.


Aquamarine
Austria
Salzburg, Hohe Tauern Mts, Hollersbach and Habach valleys, Schafkopf/Breitkopf Mts area

Aquamarine, 6cm	© Harjo

Aquamarine, 1cm	© Harjo

Aquamarine in clefts in Gneisses, or Aquamarine in masses of smoky Quartz veins.


Aquamarine
Brazil
Bahia, Guaratinga (Jaquetô)

Aqua, 4,7cm	© Kristalle and Crys

Aquamarine, 1,5cm	© Kristalle and Crys

Aquamarine, 4,7cm	© Rob Lavinsky

Aquamarine, 18cm	© Rob Lavinsky

In 1990 a pocket was found containing approximately 100kg of very fine blue-green crystals, showing negative corrosion patterns, and with pencil like terminations [Luiz A. Menezes, ExtraLapis Beryl]


Aquamarine
Brazil
Espírito Santo, Mimoso do Sul, Mimoso do Sul Mine

Specimen 9x5cm	© www.exceptionalminerals.com

Specimen 4,8cm	© fabreminerals.com

Concordia mine exploits the main pegmatite. In 1990 very nice single crystals and excellent clusters composed of tapered prisms.


Aquamarine
Brazil
Minas Gerais, Doce Valley

Aquamarine 3cm	© fabreminerals.com

Aquamarine 7cm	© Russell G. Rizzo

Specimen 17,2cm	© Rob Lavinsky

Aqua 8,4cm	© Weinrich Minerals, Inc.

Several pegmatites have produced large Beryl crystals, sometimes with water-clear "eyes" inside of them. In 1992 an Aquamarine crystal measuring 1x0,5 meters, weighing 400kg, showing a perfect termination. It now resides in the Kanagawa Prefecture Museum in Tokyo, Japan. [Luiz A. Menezes, ExtraLapis Beryl]


Aquamarine
Brazil
Minas Gerais, Jequitinhonha valley

Aquamarine 8cm and 5,5cm	© Kuno Stoeckli

Aquamarine 5,5 and 7,6cm	© Kuno Stoeckli

Aquamarine 3cm	© 2001 John H. Betts

Aquamarine 6cm	© 2003 John H. Betts

Aquamarine 4,5cm	© 2002 John H. Betts

Aquamarine 4,5cm	© Joseph A. Freilich

Aquamarine 16,2cm	© Rob Lavinsky

Aqua 6,5cm	© fabreminerals.com

Aquamarine 24,5cm	© Mario Pauwels

Aqua 4,7cm	© Danny Jones

The Serinha deposit has produced important quantities of gem grade Aquamarine. In 1998, a small unnamed pegmatite in the area produced some of the world's best Aquamarine crystals. Clear, blue prismatic crystals up to 30cm in length, with pencil-like terminations. [Luiz A. Menezes, ExtraLapis Beryl]


Aquamarine
Brazil
Minas Gerais, Medina

Aquamarine 21,1cm	© Mario Pauwels

Aquamarine 5,2cm	© CCURTO08

Info:


Aquamarine
Brazil
Minas gerais, Mucuri valley, Teófilo Otoni

Aquamarine 12,3cm	© fabreminerals.com

Aquamarine 5,3cm	© fabreminerals.com

Info:


Aquamarine
Burma (Myanmar)
Mandalay Division, Sagaing District, Mogok

Aquamarine 2,7cm	© Rob Lavinsky

Aquamarine 5,1cm	© Eric Graff

Info:


Aquamarine
China
Sichuan Province, Mianyang Prefecture, Pingwu Co., Mt Xuebaoding

Specimen 6,5x4,3cm	© Jiangbin

Specimen 18,5x11cm	© Oleg Lopatkin

Specimen 10x6,6cm	© Rob Lavinsky

Specimen 3x3cm	© Sarah Sudcowsky

Aquamarine 1,3cm	© Chinellato Matteo

Specimen 5,x4,2cm	© Collectors Edge

Info:


Aquamarine
China
Yunnan Province, Nujiang Autonomous Prefecture, Gaoligong Mts (Gaoligong Shan)

Specimen 8x6cm	© rare-X.com

Specimen 2,9x2,7cm	© Jiangbin

Highlands west of the Nu river (Nu Jiang) valley.
Located in northwestern Yunnan Province, close to the border to Myanmar (Burma).


Aquamarine
India
Tamil Nadu

Emperor of India 32x16cm	© J.Ralph

Aquamarine 5cm	© Martins da Pedra

Info:


Aquamarine
Italy
Lombardy, Sondrio Province, Novate Mezzola, Codera Valley

Aquamarine 5cm	© Chinellato Matteo

Important Alpine locality for excellent Aquamarine crystals.


Aquamarine
Italy
Trentino-Alto Adige, Bolzano Province (South Tyrol), Vizze Valley (Pfitsch Valley), Griesferner glacier

Aquamarine spray 0,7cm	© Chinellato Matteo

Aquamarine 1cm	© Chinellato Matteo

Locality for Alpine cleft Aquamarine.


Aquamarine
Italy
Tuscany, Livorno Province, Elba Island, Campo nell'Elba, San Piero in Campo, Grotta d'Oggi Quarry

Aquamarine 0,5cm	© Chinellato Matteo

Aquamarine 2cm	© Sarah Sudcowsky

This is the old quarry from where a lot of the best elbaites and tourmalines from Isola Elba, Italy, have been recovered during the 19th century.
Located near a magnesite quarry, was opened in 1825.


Aquamarine
Italy
Tuscany, Lucca Province, Apuan Alps, Stazzema, Ponte Stazzemese, Buca della Vena Mine

Aquamarine 3cm	© Marco Barsanti

Aquamarine 0,6cm	© Chinellato Matteo

The Buca della Vena mine was exploited for barite and Fe-oxides up to 1988. The mineralization is hosted within two carbonatic lenses of dolomitic metalimestones of Upper Triassic age (Grezzoni formation) and marble of Liassic age (Marble formation), interbedded with lenses of phyllites. The ore body and the hosted rocks show evidences of deformations which have been referred to a first compressive tectonic phase dating back 26 m.y.. Measured homogenization temperature in beryl crystals from the ore body ranged from 250° to 340° C, in good agreement with the metamorphic grade of the area (greenschist facies).
Carmignani et al. (1972, 1976) considered this deposit to be a metasomatic replacement of carbonate rocks, genetically connected to a hypothetical synkinematic intrusive body.
According to Cortecci et al. (1985), on the other hand, on the basis of isotope analysis of sulfates and sulfides, concluded that the deposit is sedimentary in origin and was subsequently metamorphosed and partly remobilized during the Tertiary Appenninic orogeny.


Aquamarine
Kazakhstan
Karagandy Province (Qaragandy Oblysy; Karaganda Oblast'), Ortau

Aquamarine 1,3cm	© Igor Savin

Aquamarine 2,6cm	© Igor Savin

Info:


Aquamarine
Madagascar
Fianarantsoa Province, Atsimo-Atsinanana Region, Befotaka District

Aquamarine	© J.Ralph

Aquamarine 7,7cm	© J.Scovil

Up to 7,7 cm x 4,1 cm gemmy beryl (variety aquamarine) crystals was reported in 2009 from an undisclosed pegmatite in the Befotaka district by Spirifer minerals.


Aquamarine
Mongolia
Hutag Ull Ord

Aquamarine 6,5cm	© Zbynek Burival

Aquamarine 4,3cm	© Vitezslav Snasel

Be-pegmatites in northern Mongolia.


Aquamarine
Mozambique
Zambezia Province, Alto Ligonha District

Aquamarine 2,5cm	© Martins da Pedra

Aquamarine 3cm	© Martins da Pedra

Nb-Ta pegmatite district.


Aquamarine
Namibia
Erongo Region, Erongo Mountain

Aquamarine 1,2cm	© Vítězslav Snášel

5,7cm	©

3,6cm	© Rob Lavinsky

7,8cm	© fabreminerals.com

4,1cm	© Rob Lavinsky

12cm	© Kuno Stoeckli

6,2cm	© Rob Lavinsky

6,1cm	© Rob Lavinsky

The Erongo is the largest of the late-mesozoic alkaline complexes of central-west Namibia. Situated on the fringes of the Namib Desert between Usakos and Omaruru, rising to 2319m and 40km diameter.
Very nice Aquamarine crystals have been found in the region, especially at Erongo Mountain, Davib East Farm, Klein Spitzkopje and Tubussis Farm. Also very nice combo specimens of Aquamarine with Schorl and sometimes Fluorite have been found.



Work in progress]]> Harjo Neutkens Best Minerals B Tue, 22 May 2012 18:16:56 +0000 http://www.mindat.org/forum.php?read,67,165194,165194#msg-165194 http://www.mindat.org/forum.php?read,67,165194,165194#msg-165194 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


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Bustamite
CaMn²⁺Si₂O₆ triclinic

Bustamite 6.2cm Broken Hill, New South Wales, Australia	© Rob Lavinsky

A pyroxenoid, related to rhodonite and ferrobustamite. A relatively uncommon mineral found in some metamorphosed manganese deposits, usually massive, and an occaisional lapidary material. The best specimens have arguably come from either the Broken Hill or Franklin mines, but few come out from either area these days.


Australia
New South Wales, Yancowinna Co., Broken Hill

Bustamite 4cm tall	© Rob Lavinsky

Bustamite has been found in several mines in the Broken Hill district, most notably the North mine, but also the ZC and NBHC mines (see below). It is not always easy to confirm the precise provenance however. Specimens were locally abundant and in good large crystals. Most specimens came out in the 1960's and 70's; they are now becoming rare. Most occured as somewhat rounded, pink to brown prismatic crystals in calcite with hedenbergite, galena and sphalerite. Some was quite fibrous, and pale pink to white in colour, in late stage vughs.


Australia
New South Wales, Yancowinna Co., Broken Hill, North Mine (North Broken Hill Mine; NBH Mine)

Bustamite FOV 3cm wide	© Greg Murray

Bustamite ~6cm wide	©

Australia
New South Wales, Yancowinna Co., Broken Hill, Zinc Corporation Mine (ZC Mine; NBHC Mine)

1.3 cm Bustamite xl on Galena	© Knut Eldjarn

Bustamite 10cm wide	©

Japan
Honshu Island, Kanto Region, Tochigi Prefecture, Kanuma

Bustamite ~2.5cm tall	©

South Africa
Northern Cape Province, Kalahari manganese fields, Hotazel, Wessels Mine (Wessel's Mine)

Bustamite 9.4cm tall	© Rob Lavinsky

Bustamite is fairly uncommon for the Kalahari district, but some massive pink material was suitable for lapidary purposes.


United Kingdom
England, Devon, Okehampton area (Northern Dartmoor), Meldon Quarry (British Rail Quarry; British Railways Quarry; B. R. Quarry)

Bustamite 9cm wide	© Ian Jones

USA
New Jersey, Sussex Co., Franklin Mining District, Franklin, Franklin Mine

Bustamite 20cm wide	© 2003 John H. Betts

Bustamite crystal 8cm tall	© Martins da Pedra

This is the type locality, and produced some of the best specimens (arguably equal to those from Broken Hill).



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Ralph Bottrill Best Minerals B Mon, 28 Dec 2009 09:22:44 +0000 http://www.mindat.org/forum.php?read,67,165015,165015#msg-165015 http://www.mindat.org/forum.php?read,67,165015,165015#msg-165015 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.

UNDER CONSTRUCTION


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?

Bornite Display Collections

Cu₅FeS₄ cubic and tetragonal

Though a common Cu ore, xls are quite rare. An old English name for Bornite is Horse Flesh Ore. Apparently the rose brown colour of fresh bornite resembles horse flesh. It really is amazing to watch fresh bornite tarnish quickly within a minute or so. Other old names are Peacock Ore and Erubescite alluding to the remarkable purple shades of the tarnished ore. The tarnish is a thin layer of Iron hydroxides over a layer of Blue Remaining Covellite¹. The interference colours (like gasoline on water) probably come from the layer of hydroxides.

Tarnished Bornite with Chalcopyrite 6 cm	© Carlos Medina

Bornite can be confused with tarnished Chalcopyrite, Covellite, and the much more rare Digenite. None of these are rose brown on fresh fracture. Attacking blue tarnished Chalcopyrite with a needle reveals the golden yellow Chalcopyrite underneath. Chalcopyrite and Bornite have a similar structure so one can expect an epitaxi between the two.

The structure of Bornite is based on a cubic close packing of sulfur atoms with metals in the tetrahedral sites. At temperatures higher than 228 C it crystallizes in the cubic system. At lower temperatures the metals can be disordered and there are several varieties. The lowest temperature variety is tetragonal. All crystallized Bornites with distinct xls show isometric forms.

Since the 1700's Cornwall in England has produced the most crystallized specimens which are still highly regarded and now dispersed world wide. Cornwall today produces little if any of the calbre of the old timers.The crystals on Cornish specimens frequently exceed 1 cm in size. Rarely, they were as large as 1.5 cm. The best specimens came from the mines along the foot of Carn Brea and Carn Entral, between Camborne and Redruth: Carn Brea, Tincroft, Dolcoath, and Cook's Kitchen. On old labels, locality is often just given as "Redruth", and in mostt cases, attribution to a specific mine is impossible. Good ones also came from the "United Mines" at Gwennap (another generic name, which may refer either to the St Day United Mines or to the Gwennap United Mines, both in Gwennap parish, but independent on each other), and from Botallack. (Peter Haas 2010)

Cornwall Bornite 17 cm	©

Exceptional bornites, some might say the finest, to over 2 cm were recovered here from an alpine cleft (!) in the 19th century.[www.mindat.org]

The Butte mines produced sharp crystals to a couple of cm. Messina in South Africa produced bigger crystals, but they are not quite so sharp. They get at least 5cm in size and probably get bigger than that. (David Von Bargen 2010)

The Mangula Mine in Zimbabwe I believe produced the world's finest bornite crystals. The ore was mainly massive bornite in coarse limestones. The crystals occurred as isolated, floater, very sharp, rhombic dodecahedrons with faintly striated faces and a submetallic lustre in coarsely crystaline white to buff white calcite and reached up to 7-8cm diameter. The largest I ever saw was in the Messina Mines office at Messina in 1974. It was the size of an orange. This crystal together with an 8 x 2 cm chalcocite xtl from Messina, which were both in the mine office display case, vanished when the Messina Mine shut down. I bought my crystal which is about 5cm diameter with some matrix attached from a chemist in Nairobi in 1976 who had worked in Mangula. The specimen is on display in the Branner Library at Stanford University. Apparently the University of Witwatersrand collection also had some single crystals. (Demetrius Pohl 2010)

Mangula Bornite Intergrown Trapezohedra 7cm	©

Recently some of the best ones have come from Dzhezkazgan. There were clean sharp dodecs and trapezohedrons to several cm.

1) Vaughan D J, Tossell J A, Stanley C J (1987) The surface properties of bornite, Mineralogical Magazine, 51, 285-293

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Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rob Woodside Best Minerals B Tue, 04 Oct 2011 17:59:33 +0000 http://www.mindat.org/forum.php?read,67,163098,163098#msg-163098 http://www.mindat.org/forum.php?read,67,163098,163098#msg-163098 Beryl, here for Beryl var: Aquamarine, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Emerald
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

A gemmy 1,2x1,1cm Emerald on Biotite Schist, Habach valley, Austria, extraordinary find from 2004	© Harjo

One of the most sought after gemstones, together with Diamond and Ruby. The use of Emeralds as a gemstone can be dated back as far as to Pre-Columbian civilisations in central America and to the times of the Faraos in ancient Egypt. In Egypt Emeralds where regarded as the most valuable gemstones. Some historians say the Egyptians started using Emeralds as early as 1900 b.c. whereas others reason that they started using them around 100 b.c. (Cleopatra's era). Egyptian Emeralds from the mines of Sikait have been found in the ruins of Pompei. Plinius (23-79) wrote about 12 different kinds (read: localities) of Emeralds in his Historia Naturalis, the ones from Sikait being the most valuable. Theophrastos (371-287), a pupil of Aristotoles, also wrote about Emeralds in his Peri Lithon. He writes that when one looks at an Emerald intensively it would benefit ones sight. This thought is believed to have been the origin of the Germanic name for glasses, Brille, coming from Beryll. A popular story tells us that Nero used glasses made from Emerald. In the Bible Emerald is also mentioned several times, for instance in Exodus (28) where the ceremonial dress of a priest is being described as having 12 precious stones, amongst them an Emerald. In the Middle Ages gemstone symbolism played an important role in society, Hildegard von Bingen (1098-1179), the famous Benedictine abbess, wrote about several illnesses that could be treated with Emerald.

In the Islamic world the Emerald was also of great value. One of the largest Emeralds gemstones is the Mogul Emerald. It's a 217,80 carat flawless Emerald in 1695 decorated on one side with calligraphies and on the other side with floral patterns. Most likely it's a Columbian Emerald sold to the Moguls by Spanish traders. In Renaissance Europe Emerald remained a highly prized and sought after gemstone. Emperor Rudolf II presented king August von Sachsen with a Emerald specimen in the year 1581. The 4th Earl of Marlborough had several large Emeralds in his famous gemstone collection. The Renaissance artist Dionysio Miseroni crafted a beautiful 10cm high salt cup out of a large Emerald in 1641.

Today Emeralds remain one of the most valuable gemstones. In Europe around the year 2000 one had to pay 500-1000 Euro per carat for standard quality, 2000-4000 Euro for good quality and 5000-10.000 Euro per carat for the best quality Emeralds. The highest price an Emerald gem demanded was $2.879.800 for the Harcourt Emerald in London, 1989. Nowadays a lot of synthetic Emerald is being used for gem rough, usually the sellers correctly state the synthetic origin of the stones but often synthetic stones are being sold as natural Emeralds. Normally a connoisseur won't have a hard time proving his stones are natural because natural Emeralds normally have inclusions that will tell their provenance. This might become more difficult though in the future because man made Emeralds are already being grown with a variety of inclusions. Most fine Emerald gem stone are sold with certificates from gem identification laboratories attesting to their natural origin.

Arguably the best gem rough, as well as the best Emerald matrix specimens, still come from the mines of Colombia although the last decades saw several very good new localities in Africa and Asia. If one would like to buy a small Columbian matrix specimen or loose crystal of average to good quality one will have to pay 500-2000 Euro, better and larger specimens will sell for anything between 2000 and 500.000 Euro depending on size and quality. The very best specimens will go for 500.000 up to over 1.000.000! Other Emerald specimens that sometimes demand rather high prices are the old classics from Russia, Austria and Norway, but only exceptional and classic specimens from these localities demand these high prices.

A considerable amount of debate has been going on since quite a long time about when to call a green Beryl an Emerald. In the beginning Emeralds were defined exclusively by colour, many centuries before chemical analyses began. Later, the insistence by some parties that Emerald had to contain Chromium was a commercial ploy by those connected to the Colombian Emerald industry to try to diminish competition from other sources. Nowadays Beryls coloured green by either Chromium or Vanadium are regarded as Emeralds. Green Emeralds coloured by for instance Iron are not regarded as Emeralds but are plainly called green Beryl. Other colour varieties of Beryl apart from the (green) Emerald include: Morganite (pink), Vorobyevite or Rosterite (rose), Goshenite (colourless), Aquamarine (blue), Heliodor (golden yellow to greenish yellow), Red Beryl (red). Pezzottaite (raspberry red to pink), Bazzite (deep blue) and the rare Stoppaniite (light blue) are not Beryls but are isostructural with Beryl. In the article below we have tried to concentrate on the various Emerald localities that have produced the best specimens and have been fairly prolific producers.


Emerald
Afghanistan
Badakhshan Province (Badakshan Province; Badahsan Province), Jurm District, Khaash

Emerald 5,1x4,6cm	© Rob Lavinsky

Emerald 5x4,1cm	© Rob Lavinsky

Info needed.


Emerald
Afghanistan
Konar Province (Kunar Province; Konarh Province; Konarha Province; Nuristan), Narang District, Badel Mine (Budel Mine)

6x5cm	© Rob Lavinsky

FOV 2cm	© Rob Lavinsky

A small emerald mine in a pegmatite vein that is 20 m long and up to 0.5 m thick. The deposit is largely mined out.


Emerald
Afghanistan
Laghman (Lagman; Nuristan) Province

6,4x5,5cm	© H. Obodda

4,5x3cm	© Aymeric

Beryl is especially abundant in the Kunar area, but the gem varieties, aquamarine and morganite, are found mainly in the Laghman district, where they occur with the basal pinacoid characteristically well developed. Loose crystals and crystals on matrix have been recovered. The tint varies from pink to brownish pink. Gem aquamarine crystals of a beautiful, intense blue have shown up, but it is possible that this discovery was made at Gur-Salak in Kunar. [Dr. Pierre Bariand]
On the Peshawar gem market when asking about Afghan emeralds you may also encounter green Beryl from the Laghman province, which is also an Afghan province. Laghman is located between Kabul and the Pakistani border. Typically green Beryl from Laghman are not green enough to be called Emerald. But attractive large size and clean light green stones are produced in that area. [V. Pardieu, G. Soubiraa, 2008]


Emerald
Afghanistan
Pansjir (Pansjeer) Province, Hessa-e-Say District, Pansjir (Pansjeer) Valley

Emerald crystal, 3x1x1cm	© Dan & Diana Weinrich Minerals

Emerald crystal, 1,25cm	© Rob Lavinsky

Maybe Plinius referred to the Emeralds from the Pansjir valley when he wrote about the "Smaragdus from Bactria".
The Emeralds occur in Metasediments and Metagabbros through which Quartz-Ankerite veins run. The best material comes from the Mikeni and Khenj mines, usually in gem quality crystals up to 5 carat. Crystals up to 10 carat or more are rare. The modern discovery of these stones was 30 years ago near Bismal. Currently the Emeralds are mined in 3 main areas: The Bismal-Riwat area, the Ringe and the Mukeni-Zara Kel areas. The production in Panjshir seemed to be still strong especially in small sizes Emeralds but the number of miners seems to have dropped compared to the 1980's. Currently around 1000 miners are possibly working the Panjshir mountain large deposit. The prospective for the future looks good as new mines open regularly and seems to produce fine stones. [V. Pardieu, G. Soubiraa, 2008]


Emerald
Australia
New South Wales, Clive Co., Torrington

5,1x4,2cm	© A&M

6cm	© Andrew Tuma

Torrington is a small village in County Clive and is about 13 miles north west of Deepwater and about 18 km NNE of Emmaville.
Numerous mines and deposits are located in and around Torrington.
The mines listed as being near Torrington are located in County Clive.
Note: Other mines listed as being in the "Torrington district" are located in County Gough.
Some specimens from here can be described as "emerald banded beryls". These are generally only up to 2cms.


Emerald
Australia
Western Australia, Cue Shire, Cue, Poona

Emerald crystal, 3cm	© Mark Rheinberger

14,5cm	© Andrew Tuma

Emerald crystal, 2,8cm	© Andrew Tuma

Emerald crystal, 1,6cm	© TVM

The Emeralds occur as porphyroblasts in Biotite-Phlogopite Schist. The crystals show a nice intense green colour although gem quality crystals are rare. The Emeralds get up to 4 cm long although crystals up to 15 cm long have been found.
Almost all Western Australian commercial emerald production has come from the Poona district, 500 km NE of Perth. Here emeralds were first discovered by the prospector A.P. Ryan in 1912. At Poona green beryl and emerald occur in both the intruding quartz-beryl pegmatite and biotite-phlogopite schists that border the intruded greenstones. At Poona emeralds occur in association with beryl, quartz, albite, oligoclase, topaz, tourmaline, fluorite, biotite, phlogopite, lepidolite, zinnwaldite, margarite, talc, tremolite, muscovite, scheelite, chromite, apatite, manganotantalite, and monazite.
The principal mine in the region, the Aga Khan Deep mine, has a colourful history. It has been intermittently worked both as an open cut and more recently (1977-1981) as an underground operation. In over seventy years the Aga Khan mine has yielded an estimated 10 kg of mostly low value emerald. Inevitably difficulties associated with economic mining and recovery of mostly low grade emeralds from their tenacious enclosing mica schist once again forced the temporary closure of the Aga Khan mine. Many small-sized open cut mines are located to the east of the Aga Khan Deep Mine. These include the Quartz blow, Mid section, Solomon, Reward, and Lee’s trench open cuts.Other emerald mining areas around the Poona District include the Emerald Pool mine, 16 km south-west of Poona, and the Poona East Emerald mine about 10 km east of Poona. [Grahame Brown]


Emerald
Austria
Salzburg, Hohe Tauern Mts., Habach Valley, Nasenkopf Mt., Leckbachgraben (Leckbachrinne), Emerald deposit

Emerald crystal, 2,1x1,1cm	© Harjo

Emerald in Biotite Schist, 5x5cm	© Harjo

Emerald, 2,6x1,1cm, in Muscovite Schist	© Harjo

Emerald 1,1cm	© Harjo

Layer of talc-actinolite schists with inclusions of blastomylonitic rocks (serpentinites and talc schists) and Emerald-bearing Biotite-Chlorite schists, intercalated between Scheelite-bearing banded gneisses (including Cu, Fe and Bi sulphides) and amphibolites of the Habach formation. This association of rocks trends from the Hollersbach valley in the east to the Untersulzbach valley in the west, and meanwhile Emeralds were also found in its outcrops in these neighbouring valleys.

An Emerald mine was first mentioned in 1797, but the deposit was probably worked much earlier. The present mine with its four adits (named A, B , C and D adit) was started in 1860, by the jeweller Samuel Goldschmiedt of Vienna. In 1896 the lease was taken over by the "Emerald Mines Ltd." of London., who worked the deposit until 1913. During the following years, the mine was intermittently worked by different owners until 1949, when it was abandoned. Since 1964, it is privately owned, but worked only sporadically. Presently (2009), it is owned by the strahler Andreas Steiner of Bramberg. In general, the Emeralds are of rather low quality; specimens suited for cutting are rarely found. Occasionally however good to excellent specimens have been found, both matrix specimens as well as gem rough. The biggest gem quality Emerald crystal was found in the 1970s in the sedimentary deposits of the Sedl below the Emerald mine. It weighed 128 carats and was of outstanding quality. In 2004 excellent gem quality Emeralds on Matrix have been found in a spot just below the mine, apparently it was one of the few spots in the Leckbachrinne that had not been extensively searched. Fantastic matrix specimens up to 50cm large littered with Emerald crystals come from the collection of Aloïs and Andy Steiner, they can be seen at their private museum as well as in the museum Wilhelmsgut, both in Bramberg, Austria. The Emeralds usually contain inclusions of a wide variety of minerals.


Emerald
Brazil
Bahia, Brumado (Bom Jesus dos Meiras), Serra das Éguas

Emerald 7x4,5x4cm	© Rob Lavinsky

Emerald 3,8x2,4cm	© Rob Lavinsky

The Serra das Éguas district is also known in the literature as the Brumado district (Cassedanne & Cassedanne 1978). It is a large hilly area (approx. 5 x 15 km2) with several magnesite (& talc) pits around Brumado. One of the world largest magnesite deposit is located in this district. Very fine Emerald specimens have been found in the deposit during the heyday of its production in the 1920s. After that the locality only saw sporadic activity.


Emerald
Brazil
Bahia, Campo Formoso ultramafic complex, Campo Formoso, Socotó emerald deposit

Large Emerald 12cm	© Kuno Stoeckli

Emerald 10cm	© Kuno Stoeckli

Info:


Emerald
Brazil
Bahia, Campo Formoso ultramafic complex, Pindobaçu, Carnaiba Mine

Emerald, scale 1 Inch, rule 1cm	©

Emerald 6,5x5,5cm	© vasco trancoso

The mica schists of Carnaiba, discovered in the 1963, may contain the most extensive Emerald deposits in the world. The largest cut emerald (86,136 carats) was found in Carnaiba in August 1974. The mining region is situated 30 km south of Campo Formoso on the western edge of the Serra de Jacobina Mts. The quality of the Emeralds was rather poor so they didn't achieve a prominent position on the world market. Until the early 1980s Carnaiba was the prominent Emerald producer but after the discovery of the Goias deposit Carnaiba lost it's prominence. In the 1990s the production took of again.


Emerald
Bulgaria
Rila Mts, Urdini lakes

Emerald, crystal 2x1cm	© Marcus Vau

Emerald occurrence, associated with a desilicified pegmatite vein that follows the contact between biotite gneiss and talc schist. Emeralds are concentrated in plagioclase-rich parts of the pegmatite and in contacts with phlogopite-rich zones.
The occurrence is situated in the area of Urdini lakes in Rila Mts (mountain range in southwestern Bulgaria and the highest mountain range of Bulgaria and the Balkans, with its highest peak being Musala at 2,925 m).
This locality is in a National Park and collecting is forbidden.


Emerald
China
Yunnan Province, Wenshan Autonomous Prefecture, Malipo Co.

Emerald 17x11,5x5,5cm	© Safaa Yu

Emerald 6,5x7x8cm	© Safaa Yu

The Emeralds occur in either Metapegmatites or in Fluorite bearing sulphide rich Biotitegneises. Arguably the best Emerald locality in China, the crystals can get up to 15 cm in length. Many specimens are oil treated. Good to excellent quality specimens are quite rare on the market and therefore demand high prises.


Emerald
Colombia

The Colombian Cordillera Real boasts almost 200 Emerald localities, they occur in a roughly 100 km wide belt that can be divided into two separate districts: the western area also named Vasquez-Yacopi mining district (with mines such as Yacopi, Coscuez and Penas Blancas) and the eastern district, also named Guavio-Guateque mining district (with mines such as Chivor, Gachala and Macanal). Practically all the above mentioned mines were already known by the pre-Colombian inhabitants before the Conquista. Long before the Spanish armies came to Colombia the local inhabitants mined Emeralds which they used in ceremonies as well as for trade. Through trade Colombian Emeralds found their way to the Mayas, Incas and Aztecs. On the 12th of march 1537 Capitan Valenzuela hold the first Somondoco (today Chivor) Emeralds in Spanish hands. It took another 22 years before the Spanish also owned the Muzo mine, it took so long because the Muzo and Colimas tribes maintained a strong resistance to the Spanish.

Two more recent mining areas are La Pita and Polveros. They are situated between the Muzo and Cosquez mines.
The geology in both regions is the same: Calcite, Dolomite and Feldspar dike, cleft and fissure fillings in schistose breccias contain hydrothermally formed crystals up to 10 cm [Alfredo Petrov 2005]. Most crystals however are much smaller. The Emeralds are found attractively free standing inside pockets in Carbonate-Pyrite veins that are lined with Calcite , Pyrite and Albite crystals. Accompanying minerals in the western area are: Calcite, Dolomite, Albite, Quartz, Pyrite, Fluorite, Apatite, Muscovite, Tourmaline, Parisite and Baryte. For the eastern region these are: Calcite, Pyrite, Dolomite, Quartz, Albite, Goethite/Limonite, Hematite, kaolinite, Sericite, Halloysite, Allophan, Muscovite, Fuchsite and Hyalite.

Today the large mines are operated by large conglomerate companies such as Tecminas, Coexminas, Esmeracol and Sociedad Esmeraldy. Recently some cooperatives have been formed by miners who have leases on mines and mine Emeralds. Apart from that the classic Guacueiros (independent adventurers, fortune seeking prospectors and sometimes outlaws) still prospect for their lucky find that could change their poor living standards. This comes with a rather harsh "Wild-West" atmosphere.....

Emerald
Colombia
Boyacá Department, Guavió-Guatéque Mining District, Chivor Mine

Outstanding Emerald, scale is 1 Inch with rule at 1cm	©

Emerald 4,5x2,3x3,3cm	© fabreminerals.com

Emerald 3x3x2,5cm	© FotoWeb

Chivor (or Somondoco) has delivered some of the most outstanding Emerald crystals and specimens in the world. In 1911 the German prospector Fritz Klein started organising the mining in Chivor and in 1920 he found one of the largest flawless Columbian Emeralds, the "Patrizius", weighing 630 carats. The "Patrizius" was named after St Patrick, the patron Saint of the green Isle of Ireland.


Emerald
Colombia
Boyacá Department, Guavió-Guatéque Mining District, Gachalá

Emerald 1,3x1,1x0,9cm	© fabreminerals.com

Emerald 1,4x1,3x0,8cm	© fabreminerals.com

Interesting locality for Gastropod fossils completely replaced by micro Emerald crystals.


Emerald
Colombia
Boyacá Department, Guavió-Guatéque Mining District, Buenavista Mines

Emerald, Calcite, scale 1 Inch, rule 1cm	©

The Buenavista group of mines is located in the municipality of Ubala. The geology and mineralogy are similar to that of Chivor, and indeed the areas are adjacent to each other. Mina Buenavista Jaja, including claims La Perla, La Cueva, La Laguna, Buenos Aires is separated from Chivor by the Rio Rucio. Workings are underground in slate, with Emerald mineralization more of less in hard argillites. [John Sinkakas]


Emerald
Colombia
Boyacá Department, Vasquez-Yacopí Mining District, Maripi, La Pita, La Pita Mine

Emerald 5,1x1,1cm	© fabreminerals.com

Emerald on Calcite, 5x4,5cm	© fabreminerals.com

Emerald 7,9x5cm	© www.exceptionalminerals.com

Emerald crystal 1,3cm	© Albert Russ

Excellent Emeralds have come out of la Pita mine over the last years. Loose crystals are on the market as well as fantastic matrix specimens of clear Emeralds with a good colour on Calcite crystals. Outstanding specimens demand very high prices.


Emerald
Colombia
Boyacá Department, Vasquez-Yacopí Mining District, Muzo, Coscuez Mine (Cosquez Mine)

Emerald, Calcite 3,5x3x2,5cm	© 2002 John H. Betts

Stunning! 4,8x3,4cm	© www.exceptionalminerals.com

Emerald, Calcite 4,2x5cm	© Joseph A. Freilich

Emerald, Calcite 10x7cm	© FRANCO LAZZARI

In the year 2000 the Esmeracol company operated 5 shafts and 25 adits in Coscuez. Apart from 3000 miners around 10.000 Guacueiros were active. Around a quarter of the annual Colombian Emerald production is believed to come from Coscuez. Many outstanding Emerald specimens have left the Coscuez mine along with many carats of choice gem rough. Both demand very high prices on the market.


Emerald
Colombia
Boyacá Department, Vasquez-Yacopí Mining District, Muzo, Muzo Mine

Emerald, Calcite 5,4x5,2x5,1cm	© Rob Lavinsky

Emerald, Calcite 3,3x3,1x3cm	© Michael C. Roarke

Emerald 5x3x2,5cm	© Rob Lavinsky

Trapiche Emerald scale 1 Inch rule 1cm	©

Trapiche Emerald 0,7cm	© Luciana Barbosa

Trapiche Emerald 1cm	© Luciana Barbosa

The Emeralds are usually found in pockets, or embedded, in Calcite veins traversing the Emerald formation; rarely embedded in that formation itself or in the Cenicero. Closely associated minerals forming the Emerald gangue are: Calcite, Dolomite, Parisite, Pyrite, Quartz, Barite, Fluorite, and Apatite, the last three very rare. The Emerald occurs as six-sided prisms with base, some with rarer forms also. Few crystals are larger than the thumb. Most crystals are clear when first taken from the matrix, but later develop cracks; some fall to pieces upon removal.
Choice specimens show a rich green colour surpassed by the product of no other locality. Some crystals display zones of colour; a few are dark to black with inclusions of carbonaceous matter. In some specimens recently found, the carbonaceous matter is arranged in a six-rayed figure centring about a tapering hexagonal core. One such specimen was examined optically in basal section and proved to be of the same orientation throughout; it therefore does not represent a twinned crystal as suggested by Lleras Codazzi. Its re-entrant angles are presumably the effect of solution and the disposition of the carbonaceous inclusions, the expression of crystallizing forces, as shown also, for example, in Chiastolite.
The most famous single Emerald crystal from Muzo is the "Giant of Muzo", standing 8,9 cm tall and weighing an incredible 1759 carats. The flawless superb gem quality crystals is kept in a safe in the National bank of Colombia in Bogota, its value must be incredible. Choice specimens from Muzo demand extremely high prices today. [Part of the info is (c) Pala International]


Emerald
Egypt
Red Sea Governorate, Eastern Desert, Sikait-Zabara region, Emerald mines (Gebel Zabara; Wadi Abu Rusheid; Wadi Gimal; Wadi Sikait; Wadi Umm Debaa; Wadi Umm Kabu)

Emerald 1,5cm	© richard@denul.net

Emerald 2,5cm	© richard@denul.net

Ancient emerald mines (2000 B.C. - 1200 A.D.), said to be the famous mines of Cleopatra. Rediscovered 1818. Egypt was the source of almost all emerald in ancient times. Found in pegmatitic quartz veins traversing mica and talc schists. Thousands of open pits and underground workings.


Emerald
Italy
Piedmont, Verbano-Cusio-Ossola Province, Ossola Valley, Vigezzo Valley, Trontano, Pizzo Marcio

Emerald, FOV 2cm	© Chinellato Matteo

Emerald, 5x3,8 cm	© Rob Lavinsky

Pegmatite locality known for its Emeralds, although it is of no economical interest.


Emerald
Madagascar
Fianarantsoa Province, Vatovavy-Fitovinany Region, Mananjary emerald District, South Zone, Morafeno

Emerald 125x78x55cm	© J.Ralph 2008

Emerald 4,5cm	© K.E.Larsen

One of the richest emerald mines in Madagascar. It is located 8 km south of Irondro in the Mananjary region in the Eastern part of Madagascar. Several tons of Emerald have been extracted from this area within the eighties. But as it is the case with most of the mines, a small quantity of them were usable as gem. Actually, many of them contain a white core visible in the centre of their axis of crystallization. If we want an untreated good coloured Emerald the stones will have to be sawn in small parts in order to keep the green material. The Emerald occurrence provided quality stones since 1975 until 1993. Their professional exploitation began in the middle of the eighties. The first listed discovery was reported in 1911 by the geologist Levat. Then, during the colony, a settler called Bourgeois discreetly exploited the green stones. At the time of their departure, the settlers who worked the Emerald mines in the area, warned the natives against the bad spirits which could be in the holes. As a result the gems slept for 15 years. [GGGems]


Emerald
Mozambique
Zambezia Province, Gité, Rio Maria III Mine

Emerald 3x1,5cm	© Martins da Pedra

Emerald 3x2cm	© Martins da Pedra

Emeralds in biotite-phlogopite-talc schists which formed from alteration of Precambrian ultramafic rocks.
Located 1 km west of Mt.Uapé (678 m) and 20 km NE of Morrua.
Called Maria III emerald mine by Schappmann (2005)


Emerald
Nigeria
Plateau State, Jos Plateau

Emerald 2,6x1,6x1,4cm	©

Emerald 3,9cm	© Rob Lavinsky

Emeralds from miarolitic pockets. The Emeralds can be exceptionally large and very well formed. Debate has been going on for quite a while weather the Nigerian Emeralds could be named as such, or rather green Beryl.


Emerald
Norway
Akershus, Eudsvoll (Eidsvold), Minnesund, Byrud Emerald Mine

Emerald FOV 2cm	© OT. Ljostad

Emerald 0,9cm	© OT. Ljostad

Classic European Emerald locality. For the first time mentioned by Websky in 1876. First mining commenced in 1880. The Emeralds are usually rather small but crystals up to several centimeters have been found. A 5 cm large crystal on Matrix is in the Museum of the Humboldt University in Berlin, Germany. There is a persisting rumour that one of the Emeralds in the crown of the English queen is from Byrud. Whether or not this is true might be hard to establish, while the records of the mining company so far remain lost.
The Emerald-bearing pegmatites are located at the north-western border of the Oslo Rift Valley. This rift valley of Permian age (280-230 m.Y.) is characterized by extensive alkalic igneous activity. Beryl is by far the most spectacular mineral. The colour varies from yellow, green to intensive blue. The majority of the Beryl is found as Emerald in all kind of shades of green. From pale to intensive green, from translucent to absolutely clear. Large Emerald crystals of true gem quality are nowadays extremely rare. But small Emerald crystals up to 5 mm of length and with a thickness of 1-2 mm of gem quality are not really hard to find. Especially nice are the even smaller, free-standing Emerald crystals in miarolitic cavities in the Feldspar. Important detail, is that the colouring agent in the beryl from Byrud is Vanadium, and not Chromium. The Vanadium is derived from the shales in which the pegmatites were injected, and which contain a significant amount of this element. Blue coloured beryl -aquamarine- is very rare at Byrud. [Ronald Werner]


Emerald
Pakistan
North-West Frontier Province, Malakand Region, Swat District (Swat Valley), Gujar Killi (Gujar Kili) Valley deposit

Emerald 2,5x1,7cm	© H. Obodda

Emerald, FOV5,2x3,70,9cm	© Christian Bracke

Pakistan's richest Emerald deposit. Emerald crystals are usually 1-2 cm although crystals up to 10 cm have been found. The Emeralds occur in a Talc-Carbonate Schist and are easily removed from their matrix. maybe that's the reason that good matrix specimens are rare on the market. Most of the Panjshir and all the Swat Emeralds on the local market are small stones and larger Emeralds often appear to be from Chinese origin. Most of the Swat material are the traditional small size stones with strong colour zoning and high saturation which are known to come from the area. The Panjshir stones are commonly larger than the Swat Emeralds, they had for the best quality an attractive lustre in a wide range of green, from yellowish green to blueish green. Finally the Chinese material is usually more saturated and more evenly coloured than the Panjshir stones with bluish green being the dominant colour but globally the Chinese Emeralds have a lower lustre and transparency compared to the gems from the Panjshir mines. [V. Pardieu, G. Soubiraa]


Emerald
Pakistan
Northern Areas, Gilgit District, Haramosh Mts., Khaltaro (Rayiud; Kaltoro)

Emerald 2,9cm	© H. Obodda

Emerald 4,9cm	© Aymeric

Village 6 km north of Sassi, with an emerald-bearing pegmatite field located at 4500 m elevation in the northwest Haramosh Mts.


Emerald
Russia
Urals Region, Middle Urals, Ekaterinburgskaya (Sverdlovskaya) Oblast', Ekaterinburg (Sverdlovsk), Malyshevo, Tokovaya river (Tokovaia river), Emerald mines (Izumrudnye Kopi; Malyshevskoe deposit)

Emerald, Phenakite 12x10cm	© www.exceptionalminerals.com

Emerald scale 1 Inch, rule 1cm	©

Emerald, 7,7x6,3cm	© Dan Weinrich

Emerald, 12,3x7,6cm	© Oleg Lopatkin

Biggest and oldest of the Russian Emerald localities, discovered near the Tokawaja river in 1830 by the farmer Maxim Koshewnikow. Until the end of the 19th century mined for collector specimens. In 1899 the export of gem rough commenced and in 1918 the locality became the world largest producer of Emerald. Between 1940 and 1950 the mining of Beryllium for Nuclear reactors started, Emerald being merely a by-product from then on. The Emeralds formed as porphyroblasts in Biotite Schist and are accompanied by Phenakite and Chrysoberyl (also as Alexandrite). The Museum für Naturkunde in Berlin, Germany, owns an Emerald measuring 13 cm that was a gift from Tzar Nicholas to Alexander von Humboldt in 1832. Classic specimens command high prices on the market today.


Emerald
South Africa
Limpopo Province, Murchison Range, Gravelotte, Gravelotte Emerald Mine

Emerald in Biotite schist 11x7cm	© Peter Lyckberg

xl 1,3cm	© Dan & Diana Weinrich Minerals

Emeralds crystallized where Beryllium-bearing, potassium-rich pegmatites intruded into ultramafic komatiitic schists of the Murchison Greenstone Belt. Emeralds are principally hosted within the biotitic alteration envelope that surrounds the pegmatite; these represent localized zones of intense potassic alteration. A minor amount of emeralds is hosted by the pegmatite. The occurrence was discovered in 1927, Mining from 1929-1937 produced 664,585 carats. From 100m deep Cobra pit and some underground workings. Most were small but some stones up to 10 carats have been facetted. Found in a biotite schist associated with schorl and molybdenite. Emerald crystals to at least 3cm were found. [David van Bargen]
Emerald production from 1929 to 1986 is estimated at 23,000 kilograms of varying grades. Current reserves are estimated at 17,000 kilograms of Emeralds hosted in 1,692,000 tonnes of ore. Emeralds produced at Gravelotte are small, but of good colour and quality. Out of the total production, 30 % of recovered emeralds are saleable, and 2-3 % of these are gem-quality stones. Rough stones sell for $100/carat; top quality cut stones fetch up to $8,000/carat. [Dick Hutchinson]


Emerald
Spain
Galicia, Pontevedra, A Cañiza, A Franqueira

Emerald crystal 5cm	© Echevarria

Emerald 12x9cm	© Echevarria

It is not very well know but in the northwest of Spain, in the countryside, it is possible to find some reasonable Emeralds.
The locality is situated on private property.
More info to come....


Emerald
USA
North Carolina, Alexander Co., Hiddenite

The exceptional "NAEM" Emerald, 19,5cm

Emerald, Quartz 4x3,3x2,3cm	© Rob Lavinsky

Emerald 7,8x5,5cm	© www.exceptionalminerals.com

Emerald 4x2,7cm	© Keith Williamson

Very large Emerald cluster, scale at bottom is 1 Inch, rule at 1cm	©

The first Emeralds were found in Hiddenite in 1875 by J.A. Stephenson. Emeralds up to 11 cm weighing 1686 carats have been found in Hiddenite. Recently an exceptional Emerald specimen was mined that was featured in the 2008 Tucson show. This exceptional Emerald specimen was mined in 2003 and is called the "NAEM Emerald" (NAEM stands for North American Emerald Mine). The crystal is 19,5 cm long and weighs 1869 carats, all this in excellent gem quality and dark green colour, the crystal has an etched surface typical to those from Hiddenite. G.F. Kunz writes about Alexander County Emeralds in his book "Gems of North Carolina": Some peculiar features pertaining to the emeralds and beryls from this region, are particularly noted by Mr. Hidden. "They appear," he says, "as though filed across the prismatic faces. The basal plane is also often pitted with minute depressed hexagonal pyramids, that lie with their edges parallel to one another, and to the edge of the di-hexagonal prism. Rarely though crystals are found with perfectly smooth and brilliant faces. The emerald colour is often focused on the surface and fades gradually to a colourless central core, which feature is of exceeding interest when the genesis of the mineral is considered. A similar etching or corrosion appears in beryls from Colorado, and those from Pala, California. A remarkable fact is that we have here a green beryl (emerald) and emerald green spodumene (hiddenite), and in the Pala, California, mine, we have lilac spodumene (kunzite) and pink beryls." [InternetStones.com]


Emerald
USA
North Carolina, Mitchell Co., Spruce Pine District

Emerald 1,9x1,6x1,4cm	© Rob Lavinsky

Emerald 5,5x2,5x2cm	© 2003 John H. Betts

Many mines are located in the Spruce Pine-Little Switzerland area pegmatites, quite a lot of them have yielded Emerald specimens and can be visited today for fee collecting, the most famous of them is the Crabtree Emerald mine.
Mining operations at the Crabtree Emerald Mine began in July of 1894 by J.L. Rorison and D.A. Bowman. The emeralds at the mine occur in a pegmatite vein approximately five feet wide with well defined walls. In addition to the emeralds, the vein of quartz, feldspar and mica carries several other minerals to include: garnet, schorl, yellow and green and white beryl, fluorite, etc. Mineral rights to the Crabtree were aquired by the American Gem and Pearl Company of New York in 1905. The company operated the mine several years and marketed the rock as "emerald matrix". The material was cut en cabochon. Although most of the gem material was sold as "emerald matrix", early mining operations did produce fine clear gems suitable for faceting. The deeper the shaft was sunk, the larger the emeralds that were found, many up to one inch in diameter and one inch long. The American Gem and Pearl Co. discontinued operations in 1908. The mineral rights to the property were then purchased by Edward Fortner and J.P. Grindstaff. In recent years the Crabtree was mined commercially from 1968 to 1974 during which time, fee collecting was allowed on the dumps. In the 1980's the mine was closed for some time. The mineral rights were purchased in 1984 by the partnership of Ted Ledford, Bert Roper and Dal Duppenthaler, the new owners actively mined the site. In 1985 the mine was called "Gem Haven" and public collecting was allowed on the dumps at the mine. As of 1994 the mine was closed and has set idle for many years with the occassional collector visiting the site. In 2003, Bert Roper and Dal Duppenthaler aquired sole ownership of the mine. Today, in an agreement with the Mountain Area Gem and Mineral Association, the mine has been reopened to the public under the management of the M.A.G.M.A. Club. [M.A.G.M.A.]

The geologic history of the Spruce Pine Mining District is as fascinating as it's mining history. About 380 million years ago, the African Continent was being forced toward the Ancestral Eastern North American Continent by plate tectonic force. The subduction, or forcing down of the Oceanic Crust underneath the North American Continent produced tremendous friction-generated heat from the two colliding continents. This friction-generated heat in excess of 2000 degrees melted the surrounding rock 9-15 miles below the surface. This igneous molten rock was generated under intense pressure that forced the molten rock into cracks and fissures of pre-existing rock. This molten rock under pressure is similar to hot hydraulic fluid being forced into a chamber. Due to the pressure exerted on the molten fluid, it hydraulically pushed its way through the cracks of the host rock. This opened the rock up, along with melting contact areas of the host rock and sucking up rich mineral forming fluids. As these cooled, they crystallized and became a mineral rich buried treasure. It then took an estimated 100 million years for this deeply buried (and insulated) mass to cool and crystallize. The slowly cooling mineral crystals grew within the Spruce Pine District to some of the largest feldspar and mica crystals in the world. After molten emplacement and cooling, it took millions of more years of Appalachain Mountain building and subsequent erosion to expose the deposits we see today. [Alex Glover]


Emerald
Zambia
Copperbelt Province, Ndola, Kafubu Emerald District, Kagem Emerald Mine

9cm	© J.Ralph

5cm	© Dan & Diana Weinrich Minerals

6cm	© Dan & Diana Weinrich Minerals

5,1cm	© Dan & Diana Weinrich Minerals

Emerald mine owned by the Brittish Gemfields PLC company and the Zambian government. The mine is operated by Gemfields PLC, the company produces around 20% of the global Emerald production. Kagem mine is a large open cast mine, about one square kilometre large and production in 2009 was a staggering 27,6 million carat. Equipment in the Kagem mine is tailored for retrieving Emerald crystals from the schist host rock. Occasionally wide Quartz veins are encountered that include Emerald crystals. It has proven to be difficult to get the crystals out of the massive Quartz, often only leaving shards and slivers. In 2009 Sean Gilberton and Cyrille Djankoff of Gemfields decided to save the large Quartz blocks to see if maybe good collectors specimens could come out of them. In 2009 they turned to Bryan Lees, owner of Collector's Edge Minerals, for advice on the preparation and marketing of collectors specimens. Collector's Edge took on the job and started to device a method to prepare the specimens. Because HF acid was out of the question (HF would not only attack the Quartz but also the Emeralds) they decided to remove the Quartz with air pressure powered abrasive tools and small chisels. This is a very laborious and time consuming preparation method, and each of the specimens took weeks to prepare. What came out where some of the best Emerald specimens ever seen, perfect deep green gem quality Emerald up to 15cm long on snow white Quartz matrix. Some purists however argue that preparation has gone to far.


Emerald
Zambia
Copperbelt Province, Miku Emerald Deposit

Emerald, scale 1 Inch, rule 1cm	©

Emerald 6x4cm	© mslama

The deposit is named after the Miku River, a tributary of the Kufubu, the latter a tributary of the Kafue River. It was discovered in 1931 by G. J. Baker but no work was done until some time after 1962. Th deposit was examined by Hickman and by 1973 some Emeralds had been produced. These are mostly single prismatic crystals in biotite-phlogopite schist in which small crystals of Tourmaline also occur. Associated rocks include talc-magnetite schist, quartz-amphibole-chlorite schist with fine veinlets of quartz, and larger veins of quartz. Most crystals are small, but others reach 20 cm long. Colors range from milk-white beryl to the fine green of good quality Emeralds. [John Sinkakas]


Emerald
Zimbabwe
Matabeleland South, Mweza Range (Wedja), Sandawana-Belingwe District, Sandawana Mine (Zeus mine)

Emerald 1,1x0,9cm	© 2003 John H. Betts

The Zeus Mine, nowadays called the Sandawana Mine, is a modern underground operation operating 4 shafts with about 152 meters maximum depth. It is located in the Mweza Greenstone Belt abou 360 km from the capital Harare. Apart from the Zeus mine other Emeralds deposits were discovered including Machingwe, Orpheus, Ares 3 and others. The average size of the Sandawana Emeralds is quite small (about 0,25 carat) but even the smallest crystals show a very deep green colour and excellent cutting quallity. Emeralds of up to 1,5 carat are rare although crystals up to 5 carats are found sporadically. As of today prospecting for Emerald occurrences continues in the area and new localities are being encountered ensuring many more years of Emerald mining in the area. The mine is currently owned by the Rio Tinto Zimbabwe company.


Literature about Emerald

- ExtraLapis No.21, "Smargde der Welt" 2001, ISSN 0945-8492
- ExtraLapis No.1, "Grünes Feuer unterm Eis" by Dr Günter Grundmann, 1991 ISBN 3-921656-22-2
- ExtraLapis (English) No.7, "Beryl and its colour varieties" 2005 ISBN 0-9715371-6-X
- Emerald and Other Beryls by John Sinkankas, Geoscience Press 1981
- Ural Emerald mines by V.I. Zhernakov, Mineralogical Almanac series 2009

Internet resources about Emerald

- [www.fieldgemology.org] Vincent Pardieu, about the Pansjir Emerald mines.
- [www.fieldgemology.org] Vincent Pardieu, about the Swat valley Emerald mines.
- [www.strahlen.org] Harjo Neutkens, about the Habach valley Emerald mine.
- [www.sagen.at] Josef Lahnsteiner, about the Habach valley Emerald mine.
- [smaragd.granat.at] Christian Hausen, about the Habach valley Emerald mine.
- [econgeol.geoscienceworld.org] G. Grundman, G. Morteani, about Emeralds from the Habach valley (A) and Leysdorp (RSA)
- [www.palagems.com] about the Muzo mines.
- [www.emeralds.com] about the Colombian Emerald mines.
- [www.nags.net] Ronald Werner, about the Byrud Emerald mine.
- [www.gem.org.au] Grahame Brown, about the Poona Emerald mine.
- [www.gggems.com] about the Emerald mines of Morafeno.
- [www.internetstones.com] about the mines of Hiddenite.
- [www.mindat.org] Daniel Russell, about the Old Plantation Emerald mine.
- [www.mindat.org] Daniel Russell, about the mines of Hiddenite.
- [www.sfu.ca] Dick Hutchinson, about the Gravelotte Emerald mines.

And......some Emerald trivia...

-On the 21st of June 1989 the Harcourt Emerald necklace was sold at Christie's London for $ 2.879.800,--. The necklace holds Emeralds with a total of 162,19 carat.
-On the 21st of may the highest price ever was paid for a single cut Emerald (weighing 16,38 carat, set with diamonds) at Christie's Geneva. It went for $ 1.589.000,--.
-A Columbian Emerald weighing 10,11 carat, set in a ring, was sold on the 2nd of May 2000 at Christie's Hong Kong for $ 1.149.850,--. This gives a carat price for $ 113.734,-- per carat, to date the highest carat price paid for an Emerald. [all info: ExtraLapis 21, Smaragde der Welt]

Info and photographs needed from good Emerald specimens from the following localities: Mozambique, Namibia, Tanzania, Somalia, Wolodarsk (Ukraine), Vietnam, Finlayson Lake (Canada) and others.....if any..

[Harjo Neutkens 2009]



Click here to view Beryl, here for Beryl var: Aquamarine, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Harjo Neutkens Best Minerals B Sat, 19 Nov 2011 23:01:59 +0000 http://www.mindat.org/forum.php?read,67,163097,163097#msg-163097 http://www.mindat.org/forum.php?read,67,163097,163097#msg-163097 Beryl, here for Beryl var: Emerald, here for Beryl var: Aquamarine, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.

Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?

Red Beryl
A variety of Beryl Be₃Al₂Si₆O₁₈ Hexagonal

Red Beryl, 6cm specimen	© www.exceptionalminerals.com

Red Beryl is a low-alkali variety of Beryl.
The occurrence of Red Beryl is restricted to the Wah Wah mountains (Beaver County), the Thomas Range (Juab County), the Black Range in New Mexico (all in the USA) and according to Sinkankas to San Luis Potosi, Mexico.

In 1904, Maynard Bixby discovered red beryl in the Thomas Range located in Juab County, Utah. Bixby thought it might be a new variety of beryl, but the raspberry- red color did not correlate with any beryl known to exist at that time (green, blue, pink, yellow, and clear/white). W.F. Hillebrand, a geochemist from the National College in Washington, D.C., identified the mineral as a new type of beryl in 1905.
In 1912, Dr. A. Eppler named it bixbite in honor of its discoverer, now a discredited name. Laboratory analysis showed that manganese and small amounts of iron, chromium, and calcium create the raspberry-red color of red beryl. Like other beryl, red beryl has a hardness of 7.5 to 8.0 [Utah Geological Survey]
Red Beryl was first discovered in the Wah Wah mountains by Lamar Hodges in 1958. In 1977 Ed, Rex and Bob Harris bought the first claim for US$ 50.000, since then their "Ruby Violet" claim has produced gem rough and collectors specimen valued at over 35 million US$ [ExtraLapis Beryl]

Red beryl formation began with the eruption of a topaz rhyolite lava from volcanic vents. As the lava began to cool, shrinkage cracks formed, creating pathways for high temperature gases rich in beryllium to escape. Oxidized surface water also began seeping into these cracks and mixed with the rising beryllium gases. The gases reacted with the surface water, silica, alkali feldspar, and ironmanganese oxides from the lava to form red beryl crystals.
Red beryl probably grew at temperatures between 300 to 650 degrees Celsius. Red beryl is presently found at only three locations in the world: the Thomas Range and the Wah Wah Mountains in west-central Utah, and the Black Range in New Mexico.

In the Thomas Range, red beryl occurs primarily as short, flat, hexagonal crystals or more rarely as elongated, barrelshaped crystals. The crystals are generally up to 2 –10 mm long and 4 – 6 mm thick. Many of these crystals are too small to be faceted. They are found in cavities and fractures within the Topaz Mountain rhyolite that erupted approximately 6 to 7 million years ago from volcanic vents in the area.
Small crystals can be found in an area called "the Cove," where they may be attached to other minerals such as topaz, bixbyite, garnet, pseudobrookite, or hematite. Larger crystals that have been faceted into gemstones have been found in the northwest part of the Thomas Range near Wildhorse Springs.

The only known deposit of large, gem-quality red beryl in the world is from the Ruby-Violet claims in the Wah Wah Mountains of Beaver County, Utah. These are private claims and no collecting is allowed without permission from the present claim owners.
The crystals occur primarily as elongated hexagonal crystals that are up to 15 mm in length, and the largest crystal discovered to date is 14 mm wide and 34 mm long. Red beryl is generally found along large, near-vertical, northwest-trending fractures and clay-filled seams within the rhyolite member of the Blawn Formation. The rhyolite erupted approximately 18 to 20 million years ago from volcanic vents in the area.
The property has periodically been worked and continues to produce nice mineral specimens and stones suitable for faceting. Red beryl crystals from this location that have been faceted sell for an average of $2,000 per carat. For comparison, gold is currently worth $300 to $320 per ounce (one ounce is equal to 155 carats).[Utah Geological Survey]


Red Beryl
USA
Utah, Beaver Co., Wah Wah Mts.

Red Beryl, specimen 6cm	© www.exceptionalminerals.com

Red Beryl, 6cm	© Rob Lavinsky

The most important locality in the Wah Wah mountains is the "Violet claim" (see above). It produced fantastic specimens of deep red Beryl on Rhyolite matrix. Accessory minerals are Topaz, Pseudobrookite, Byxbyite and Spessartine Garnets.
Another locality that produces world class Red Beryl specimens is Jets Nos. 1-8 Claims (Harris Red-Beryl Quarry), Gillies Hill, although it might refer to the same claim of the Harris brothers. Maybe anyone with adequate knowledge can clarify that.......


Red Beryl
USA
Utah, Juab Co., Thomas Range

1,4cm crystal	© Sarah Sudcowsky

0,9cm crystal	© Rockpick Legend Co.

Similar finds of Red Beryl in and on Rhyolite like those in the Wah Wah mountains have been made in the Thomas Range.
Although good specimens have been found the quality never compares to the spectacular Wah Wah mountains specimens.
The paragenesis is similar to that of the Wah Wah mountains.


[Harjo Neutkens 2009]



Click here to view Beryl, here for Beryl var: Emerald, here for Beryl var: Aquamarine, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Harjo Neutkens Best Minerals B Thu, 10 Dec 2009 15:51:38 +0000 http://www.mindat.org/forum.php?read,67,163070,163070#msg-163070 http://www.mindat.org/forum.php?read,67,163070,163070#msg-163070 Beryl var: Emerald, here for Beryl var: Aquamarine, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?

Beryl
Be₃Al₂Si₆O₁₈ Hexagonal

© Harjo

© Rob Lavinsky

© www.exceptionalminerals.com

© Mario Pauwels

© 2001, Jesse Fisher

© Jiangbin

© Chinellato Matteo

© Chinellato Matteo

© Chinellato Matteo

Beryl is one of the oldest minerals known by mankind. The origin of the name might have originated from the Greek word for blueish gems "beryllos". The Latin word "beryllus" referred to lustre and clarity.
The French word "briller" ("shining" ) and also the German word for glasses, "Brille" come from the same Latin word.
Beryl is a beryllium cyclosilicate. It is an important mineral for the industry as well as for the gem and mineral specimen markets.
Beryls have been found in considerably large sizes, in Malakilina, Malagasy a18m by 3.5m crystal was found weighing 380 tons and a tapered crystal measuring 10,06m by 1,38m was recorded by Stevens (1972, p.50) as having been found in 1950 at the Bumpus Quarry, Albany, Oxford County, Maine, U.S.A. [David Von Bargen]
Beryl occurs in a variety of colour variations, below you will see a list of the different Beryl varieties and closely related minerals.
There's also Beryl that doesn't belong to either of the below mentioned colour varieties. Among them are more or less opaque crystals in different pale colours, these are usually named "common Beryl" or in German "Gemeiner Beryll". Some of them however come in crystals with nice colour and gem quality, like for instance the fantastic Finnish green Beryls (however these are sometimes referred to as being Heliodor) and the African "golden" Beryls that appeared on the gem and specimen market over the last decade.

If you click on the the names you'll be directed to the article dedicated to the specific variety. Bazzite and Pezzotaite are isostructural with Beryl (so are a couple of other minerals). But because of their importance in the gem and/or specimen market I thought it a good idea to include their links here.
This article will only include the "common Beryls"

Go to: Emerald
Go to: Aquamarine
Go to: Goshenite
Go to: Red Beryl
Go to: Morganite
Go to: Heliodor
Go to: Vorobyevite/Rosterite
Go to: Bazzite
Go to: Pezzottaite


Beryl
Australia
Northern Territory, Harts Ranges (Hartz Ranges), Mt Palmer

Crystal 4,5cm	© Mark Rheinberger09

Crystal 3,2cm	© Andrew Tuma

Situated South of Harts Range Police Station, comprising a number of mines and unnamed diggings.


Beryl
Brazil
Northeast Region, Bahia

Crystal 5,2cm	© Rob Lavinsky

Crystal 9,2cm	© Rob Lavinsky

Info:


Beryl
Brazil
Southeast Region, Minas Gerais

Crystal 6,8cm	© www.exceptionalminerals.com

Crystal 6,3cm	© Rob Lavinsky

Although the areas mines are renowned for splendid Emerald, Morganite, Aquamarine, Goshenite and Heliodor specimens occasionally a Beryl appears that doesn't fit in any of these varieties, nevertheless they sometimes come in very good quality.


Beryl
Brazil
Minas Gerais, Jequitinhonha valley,Minas Novas, Palmital Mine

Beryl var. aquamarine, Schorl, Microcline & Mica >20 cm wide	© Renee Teresa Polityka

Here is a specimen that I have admired for about 40 years. It is a beryl from Brazil (matrix specimens of beryl from Brazil are rare). The matrix is over 25 cm in width. It resides at the Smithsonian Museum of Natural History and was photographed on July 24, 2010.
[Joseph Polityka 2010]

Like Joe, I and I can't imagine how many other collectors who visited the Smithsonian Institute, this matrix aquamarine specimen from Brazil was the aqua of our dreams. Then along came Pakistan and matrix aquas became common, but you know? this specimen still looks fine to me.
[Rock Currier 2010]


Beryl
Canada
Manitoba, Lac-du-Bonnet area, Bernic Lake, Tanco Mine (Bernic Lake Mine)

17x12cm	© Collectors Edge

Crystal 10cm	© Rob Lavinsky

A tantalum-lithium-cesium mine in the Tanco pegmatite. Owned by The Tantalum Mining Corp. of Canada (TANCO). Discovered 1930, opened 1954-1960. Reopened 1967 and closed 1982. Workings went to at least the 280 foot (90 meter) level.


Beryl
China
Yunnan Province, Wenshan Autonomous Prefecture

8x5,5cm	© Jiangbin

Crystal 5,4cm	© JSS

Info:


Beryl
Finland
Etelä-Suomen Lääni, Southern Karelia, Luumäki, Kännätsalo, Karelia Beryl Mine pegmatite

Pegmatite mine. Some years ago a pocket was found that delivered some astonishing crystals of very large gemmy etched Beryl. The best crystals have kept as specimens and many others delivered choice gem rough.
Can someone post a photo of these spectacular Beryls on Mindat?


Beryl
France
Brittany, Finistère, Menez-Goaillou-en-Coray, Pegmatite quarries

Crystal 8cm	© P L e Roch

Crystal 0,8cm	© P L e Roch

Aplitic granite cupola, with disseminated arsenopyrite, intruded in Brioverian schists.
Numerous mineralized quartz veins (pneumatolytic-hydrothermal quartz-beryl-molybdenite veins) with greisens cut the granite.Very good Beryl crystals can occasionally be found in the Finistere region.


Beryl
Germany
Bavaria, Lower Bavaria, Bavarian Forest, Tittling, Matzersdorf, Kerber Quarry

Crystals up to 10cm	© C.H.M.-Schäfer

A quarry in granodiorite ("Tittling granite" ), disseminated by pegmatite veins, famous in germany for good Beryls and other Beryllium minerals.
Located just west of the B85 road near Matzersdorf, about 3.5 km NNW of Tittling.


Beryl
Ireland
Co. Donegal, Dunglow, Sheskinnarone

Crystals up to 12,5cm	© Stephen Moreton

Info:


Beryl
Italy
Piedmont, Verbano-Cusio-Ossola Province, Ossola valley

Crystal 2,5cm	© G.Fraccaro

Crystal 7cm	© Marco Macchieraldo

Info:


Beryl
Italy
Tuscany, Livorno Province, Elba Island, Campo nell'Elba, San Piero in Campo

Crystal 0,16cm	© Chinellato Matteo

Crystal 0,15cm	© D. Preite

Pretty village near Marina di Campo. His territory is part of Mt. Capanne thermometamorphic ring; the contact granodiorite-serpentinite is rich in pegmatite veins. Pegmatites with Cs- and REE minerals.
Most of the colourless Beryls are Goshenites, of which splendid crystals have been found in the Campo area, as well as good Aquamarines and Morganites.


Beryl
Madagascar
Antananarivo Province

Crystal 4,5cm	© ARLIGUIE M

Scale 1 Inch, rule 1cm	©

Apart from the great Aquamarines, and Heliodors (and the occasional Morganite) the region offers many good specimens of common Beryl.


Beryl
Mexico
Baja California Norte, Mun. de Tecáte, El Mesquite

Scale 1 Inch, rule 1cm	©

Sinkankas reported gemmy aquamarine & golden beryl in small prismatic crystals from small vugs in a granitic pegmatite near El Mesquite village, about 27 km S of El Condor turnoff from Highway 2 (El Condor is ca. 49 km E of Tecate. The pegmatite occurs between Jassay and El Topo and is mineralogically simple, consisting largely of feldspar with some quartz, schorl, mica, rare purplish apatite, albite, and euhedral prisms of pale greenish yellow to pale golden-yellow beryl, ranging from acicular to some about 7 mm in diameter to 77mm long. Some are smooth-faced, others etched and tapered. Most contain abundant inclusions of extremely small size which render the bases opaque or only translucent but in a sharp transition: these disappear toward the terminations, the latter being transparent.


Beryl
Norway
Aust-Agder, Evje og Hornnes

Crystal 2,2cm	© 2005 M. Kampf

Crystals up to 8cm	© Olav Revheim

The Evje/Iveland district host several hundred small pegmatite quarries predominantly worked for quartz and feldspar. The area is known for good quality REE minerals and the rare scandium mineral thortveitite. Several quarries has also been worked for beryl, and in the years after WW2, beryl was the main product from a few quarries.

Beryl in these pegmatites occurs embedded in feldspar and quartz and are normally found as opaque greenish/yellowish crystals, although gem quality material are known. The Havåsen quarry has produced some very large crystals. Already in 1933 a crystal weighing around a metric ton was found, and in 1947 a 3,25m long crystal with a 1,3m diameter appeared. This is the biggest beryl crystal found in the area. Rosenquist (1949) describes how 5 crystals with a total weight exceeding 13 tons where extracted the winter 1947-48. Some of this material had " large transparent areas one could see far into", a 270kg piece was one of them. A deep blue aquamarine "leftover fragment" was cut into a 10ct faceted stone.

In 1967 a group of large crystals was found in the Beinmyr quarry. The largest crystal was 3,15 m x 42-54 cm weighing about 1,65 tons. Several other crystasl was found in this period and the book "Iveland 5, mining" contains interviews with former miners how they worked this mine: " We where working for feldspar and mica, and we had just sent away 1 1/2 truckload of muscovite when we suddenly hit a large beryl "nest". After a blast I could se the top cap of a beryl crystal in the wall, and we extracted a total of 3,5 tons from this nest. There where both large and small beryls. The biggest one where 300kgs, and I was able to save a 80kg single crystal with an intact end-cap..... Of other minerals we found columbite and monazite. The monazite was sparse but we found nice, large crystals to hand size. They had a wonderful colour and beautiful crystal development. They probably weighed a few kilograms each."

Large beryls has also been found later. In the 70-ties, Bjarne Engestøl found quite a lot of beryl at Knipane. The largest crystal exceeded 1m. This time, the gemmy material was secured and both stones with a deep yellow and rather deep aquamarine was cut.

Until 10 years ago, Arild Omestad spent a week a year working the Brattekleiv quarry for beryl specimens.This quarry is qute rich in beryl and the size of the crystals are more "cabinet friendly" than the the ton sized crystals.

Many of the crystals may contain gemmy areas, but gem material was not kept as such until the late 60-ties and later. The mining operations was then rapidly declining. Some collector gems has been made, and in particular Ivar Gautestad collected and faceted some material. He has amongst other prepared and sold a handful sets containing 9-12 faceted beryls in different colours from colourless through yellow, green and blue. [Olav Revheim]


Beryl
Pakistan
Northern Areas, Baltistan, Skardu District, Braldu Valley

Crystal 2,3cm	© H. Obodda

8x7cm	© 2006, Jesse Fisher

Info:


Beryl
Poland
Lower Silesia (Dolnośląskie), Strzegom-Sobótka Massif

Crystal 4cm	© SpiriferMinerals.com

Crystal 2cm	© G. Bijak

Pegmatites and hydrothermally altered granite.


Beryl
Portugal
Viseu District, Ferreira de Aves, Aldeia Nova, Assunção Mine

Crystal 9,5cm	© Jorge M. Alves

Crystal 15cm	© k. ludwig

Quarry famous for huge beryls several meters in size.


Beryl
Russia
Eastern-Siberian Region, Transbaikalia (Zabaykalye), Chitinskaya Oblast', Nerchinsk (Nertschinsk), Adun-Cholon Range

Crystal 11cm	© 2009 Jesse Fisher

Crystal 18,5cm	© Oleg Lopatkin

Crystal 15,5cm	© Oleg Lopatkin

Scale 1 Inch, rule 1cm	©

These Nertschinsk gem mines started in 1723 are are on three peaks of the Adun-Cholon Mountains: Hoppevskaya Gora (Schorl Mountain), Sherlovaya Gora, Soktuj Gora; and further north near the Urulga River. Most locality attributions are suspect as the gem dealers are not interested.


Russia
Urals Region, Middle Urals, Ekaterinburgskaya (Sverdlovskaya) Oblast', Sarapulka (Murzinka) District, Murzinka (Mursinsk; Murzinsk; Murzinska) Mine

Beryl var. heliodor 3.1cm tall	©

Info:


Beryl
Russia
Urals Region, Middle Urals, Ekaterinburgskaya (Sverdlovskaya) Oblast', Yuzhakovo Village, Alabashka pegmatite field

Scale 1 Inch, rule 1cm	©

Scale 1 Inch, rule 1cm	©

Info:


Beryl
Sweden
Ångermanland, Strömsund, Hoting, Lillberget

Crystal 3,5cm	© Martins da Pedra

5cm	© Martins da Pedra

Small (7-8 meter wide) quartz and feldspar quarry. Mainly known for beautiful rose quartz, which unfortunately fades.


Beryl
United Kingdom
Northern Ireland, Co. Down, Mourne Mts

Crystal 0,4cm	© Steve Rust

Crystal 1,9cm	© Stephen Moreton

Locality famous for Aquamarine although also Beryls have been found in other colours.


Beryl
USA
California, San Diego Co., Pala District

Scale 1 Inch, rule 1cm	©

4,1cm	© Dan & Diana Weinrich Minerals

The Pala district in northwestern San Diego County, California, has been a widely known source of gem and lithium minerals. Formal mining operations began in the 1870's, but the most active period was from 1900 to 1922. Several underground gemstone mining operations on Tourmaline Queen Mountain and Chief Mountain persist to this day.
The Pala district has been the subject of many science-and industry-based reports, focusing on gemology, mineralogy, petrology, physics and other facets relating to the 400 or so Rare Earth Element (REE) pegmatite dikes (outcrops, veins, ledges, bodies, deposits, lodes etc.).
The area is also often referred to as the Pala Gem Mining District, or the Pala Pegmatite District. It is a common misnomer that the term "district" is an official designation. The Pala area was never established as an organized mining district, and as such all mining claim documents pertaining to the statutes of the United States and California were filed with the Office of the County Clerk.

The Pala Band of Mission Indians, whose reservation was established for the benefit of the Cupeño and Luiseño Indians in 1891, had encompassed most of the mineral lands often referred to as the Pala District or Pala Mining District by 1903. By 1988, several Acts of Congress had appropriated all of the remaining public lands once open to mineral entry under the general mining laws for the benefit of the Mission Indians, excepting the federal mineral patents issued between 1913 and 1979 from the transfer.
Because of the significance of the Pala district's impact on San Diego's history and economy, the County's regional land use plan recognizes the importance of the gem mines in Pala, and generally encourages the immediate development of the eight federal mineral patents.

United States Mineral Patents granted in the Pala mining district by date issued:
1913 - Tourmaline King lode by F. B. Schuyler
1914 - Ed Fletcher Jr. lode by Ed Fletcher
1949 - Stewart Mine lode by Blanche C. Crane
1949 - Hiriart lode by George A. Ashley
1955 - Tourmaline Queen & Tourmaline Queen No. 3 lodes, Pala Chief lode, Goddess lode by Mildred S. Wear and Margaret S. Moore (Frank A. Salmons heirs)
1979 - Oceanview lode by Roland Reed

Pala, also referred to as the Pala Mission or Village of Pala, is the name of the town nearest to the gem-bearing pegmatite mines which are located in the nearby mountains to the north, east, and south. The town of Pala is not itself a specific mineral producing locality, except for a small-scale granite quarry which has operated for several decades on the west side of town. The mine produces gabbro and granodiorite riprap which is used locally along the roads for erosion control purposes.
The best known historical landmark in the town of Pala is the famous Mission San Antonio de Pala Asistencia campanile. Completed in 1818, the bell tower was rebuilt after collapsing during the floods of 1916. During the reconstruction of the original mission complex after the floods, several large pieces of deep purple lepidolite from the nearby Stewart mine were used in the surrounding courtyard walls as ornamental stone. The decorative lepidolite was donated by local gem miner and mineral dealer Frank A. Salmons, president and principal owner of the Pala Chief Mining Company. [Scott L. Ritchie]


Beryl
USA
California, San Diego Co., Warner Springs Co., Carmelita Mine

Crystals up to 2,4cm	© Rob Lavinsky

Crystal 2,2cm	© 2001 SLR

The Carmelita mine is located in the SW¼ sec. 36, T9S, R3E, SBM, near the southeast end of the crest of a prominent northwest trending granite ridge in the SE4 and SW4 of Section 26, T9S, R3E, SBM; about 5 miles north of Warner Springs, San Diego County, California, USA.

Situated an elevation of 4800' AMSL, the exposure is covered with dense chaparral amidst small stands of Coulter pine. The primary development is in the center portion of a continuous northwestward striking pegmatite vein up to 400 feet across, that is at least 2000 feet long and has an average dip of 40° south.
The pegmatite is enclosed in granodiorite, which contains numerous septa and inclusions of platy, impure quartzite and mica-schist; and is thought to be underlain by gabbroic country rock.

History:
The mine was discovered on April 29th, 1907, by a local Basque prospector from Warner Springs named John Peter Labat (Jean Pierre Labat), as he was hiking atop the nameless but visibly prominent physiographic feature a few miles north of Warner's Ranch, investigating an area where several masses of milky-white quartz outcropped on the surface. Sunlight and a little digging soon revealed considerable quantities of pink, blue and green tourmaline.
The great gem discovery caused Labat to quickly locate a quartz (lode) mining claim on May 1st which he appropriately named "Carmelita", and recorded at the San Diego County Courthouse on May 7, 1907. The outside lines of the claim were located between the places of John Linton and the Old Web place or Larue Flat.

Around 1910, early Chihuahua Valley homesteader and local camp outfitter Ray Mitchell, came across Labat as he was riding down the trail towards Colonel Ed Fletcher's ranch. Mitchell said that "French Pete" showed him several large (5" x 3" ) nicely colored tourmalines from recent mining, and he was taking them down to San Diego for sale.

Available data for the years 1907 through 1915 indicates that the Carmelita was the leading producer of tourmaline within this remote mountainous region of northeastern San Diego County. Records disclose approximately 26 pounds of tourmaline recovered from surface and underground workings.

By June of 1932, the Carmelita claim title was transferred to "Jeanne Marie Frey" of 3117 - 28th Street, San Diego. At the request of Frey, the U.S. Department of Interior's General Land Office issued instructions on June 24th of 1932, to perform a Mineral Survey of the Carmelita Lode claim. The survey commenced on July 11th of that year, and was performed by R. Robinson Rowe, a licensed United States Mineral Surveyor, with the assistance of Eric V. Quartly who acted as the "Chainman", and "Assistant Transitman".

Together, in pursuance of instructions received from the Office of Cadastral Engineers at San Francisco and Glendale, California, Rowe and Quartly proceeded to mark the corners and survey the boundaries of the Carmelita Lode and the Carmelita Mill Site.

Rowe's survey reported the labor expended and improvements made upon the Carmelita Lode claim, which included detailed description of the character, extent, location, and itemized value thereof. The improvements at that time consisted of 14 cuts, 6 drifts, 2 stopes, 1 trench, 9 tunnels, and 1 winze.
Using Frey's inventory which was purchased from Labat years earlier, Rowe estimated the total improvement value at this time to be $5,690. His survey concluded that a total of approximately 681 short tons of pegmatite were removed and processed between 1907 and 1932, with an average gemstone recovery value of $8.36 per ton. Jeanne Marie Frey apparently died in 1935 prior to receiving a patent grant to the lode.

Around 1935, Chihuahua Valley resident Ottis Mitchell (10 years the younger brother of Ray Mitchell), accompanied neighbor and local hardrock miner A. N. Pearson (Andy Pearson) up to the "French Pete" mine to see a large gem-pocket that Pearson had recently discovered.
Mitchell, a mining engineer graduate from the local University of Riverside, described Labat's original pack-trail which had been roughly converted into a "two-track road" to facilitate travel from "stump to bolder" of Pearson's "old Dodge" truck.
He described Pearson's discovery as a "big pocket filled with large rose-colored tourmaline crystals encased in a bluish-green powdery clay". He also recalled that the reward was exceptional for Pearson, with many large gem-grade tourmalines being recovered, yet ultimately the work was very hard, and the gemstones proved "not easy to get". It was also noted that most of the work performed by Pearson usually did not involve contracted laborers.

On August 6, 1977, Roland Reed of El Cajon and George Ashley of Pala, relocated a lode mining claim on the Carmelita mine on the deposit, naming the claim after Weber's 1963 geographical description; the "Crest Gem".
Reed and Ashley soon began development at the mine by using a track-dozer to create an access roadway from Lost Valley Truck Trail (Lost Valley Road) to the north side of the summit upon which the gem-bearing pegmatite exposure and historic underground workings were located.
Within a few months, the duo engineered over 1 mile of new roadway constructed in rugged steep slope conditions, with a relatively dramatic elevation gain of over 480 feet to the top of the ridge. Work began to extend the lateral drifts on the southwest dip slope of the pegmatite, in hopes of encountering a continuation of pocket zones removed by Labat nearly 70 years earlier.
Approximately 60 linear feet of underground workings were constructed during this period, with only a few minor pockets encountered as a result of this work, primarily consisting of quartz crystals and microcline feldspar.

Giuseppe Laddomada of Vista began an intensive exploratory program in 1978, utilizing a small track-dozer, downhole drilling and hardrock blasting to expose additional sections of productive pegmatite.
Between 1978 and 1992, two large pockets nearly 20 feet long were discovered that produced many fine tourmalines in colors of green, blue, and pink. Additionally, many excellent beryl crystals were recovered, in both blue (aquamarine) and pink (morganite) varieties. In between these areas, large quantities of smoky quartz crystals were discovered, many of which exceeded 7 lbs in weight.
In March of 1993, Erik M. Cordova of Torrance discovered a large pocket containing over 100 quartz crystals, some weighing as much as 8 lbs, with many attached to an aesthetic matrix of cleavelandite and microcline feldspar.
During a field trip in May of 1998, Bureau of Land Management (BLM) Geologist, Walter 'Buzz' Todd - witnessed the discovery of several gem-quality morganites. These beryl crystals were light-pink with etched exteriors, the largest weighing just over 7 grams. In June, of that year, the San Diego Mining Company (SDMC) received concurrence with planned surface development and reclamation activities from the BLM, setting the stage for an intensive exploration program.

During the summer of 1999, a section of pegmatite was removed within the northwestern portion of an existing trench in which was an exposed underground lateral drift. In this zone was discovered a bright pink montmorillonite clay-filled pocket measuring approximately 2 feet across, which produced nearly 200 grams of fine quality green tourmaline crystals.
The largest of these elbaite crystals measured over 4 inches long, weighing 11 grams, and 45 percent of the prism consisted of flawless rough suitable for faceting a truly museum-quality gem. Additionally, over 200 lbs of carving-quality lepidolite was recovered, along with several unique specimens of cassiterite and fluorapatite on matrix, marking the end of a colorful century for the Carmelita lode.

Beginning in 2000, exploration work by SDMC had focused along the steep pegmatite exposures located along the north and south sides of the mountain. Amidst the high-rise pegmatite boulders and thick brush, continuous pick and shovel discoveries of blue tourmaline, pink beryl and yellow quartz gemstones were been made by the crew in preparation of the portal site for the underground emergency escapeway.[Scott L. Ritchie]


Beryl
USA
Connecticut, Middlesex Co., East Hampton

4,5x3cm	© 2002 John H. Betts

Crystals up to 13cm	© Stephen E. Fritz

Apart from the nice Heliodors of Slocum quarry the area also produced common Beryl.


Beryl
USA
Connecticut, Middlesex Co., Portland

Crystal 5,4cm	© Rob Lavinsky

Crystal 26cm	© 2006 Peter Cristofono

Info:


Beryl
USA
Maine, Oxford Co.

Crystal 2,5cm	© Rob Lavinsky

Crystal 4,5cm	© Rob Lavinsky

Many granite quarries in the County delivered a fair amount of good Beryl specimens.


Beryl
USA
Massachusetts, Worcester Co., Royalston

Crystal 1cm	© 2009 Peter Cristofono

Crystal 1,5cm	© 2006 Peter Cristofono

Info:


Beryl
USA
Montana, Jefferson Co., Montana

13x10,5cm	© W.C. van Laer, 2010

5,5x5,5cm	© Wm. C. van Laer

Beryl inclusion in Quartz crystals.
While Montana isn't known for its beryls, this specimen was found in the Boulder Batholith near Butte, and is a very unusual occurrence for this mineral [William C. van Laer]


Beryl
USA
New Hampshire, Chesire Co., Alstead

Crystal 3,2cm	© 2008 Peter Cristofono

©

Info:


Beryl
USA
North Carolina, Mitchel Co., Spruce Pine District, Spruce Pine, Crabtree Mine (Emerald Mine)

Crystal 1,9cm	© Steve Bonney 2006

Crystal 2,5cm	© E Harrington

Although known for Emerald specimens the mine did produce yellow common Beryl crystals.



[Harjo Neutkens 2009]



Click here to view Beryl var: Emerald, here for Beryl var: Aquamarine, here for Beryl var: Red Beryl, here for Beryl var: Morganite, here for Beryl var: Heliodor, here for Beryl var: Goshenite, here for Best Minerals B, here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Harjo Neutkens Best Minerals B Mon, 23 Jan 2012 21:50:45 +0000 http://www.mindat.org/forum.php?read,67,158406,158406#msg-158406 http://www.mindat.org/forum.php?read,67,158406,158406#msg-158406

©

Click here for a list of articles that are not under construction but have had at least their first drafts finished.

This article is a place holder and needs someone to take it in hand and finish the first draft. If you would like to take this article in hand, leave a reply message below or contact Rock Currier via private message by clicking on the PM button next to my name at the top of the article.



This Article is Under Construction



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities? After each set of pictures there should be some descriptive text. If none appears it means that we need someone to tell us about the specimens from that locality and something about the geology of the occurrence.

Betafite
(Ca,U)₂(Ti,Nb)₂O₆(OH) isometric

Betafite, Silver Crater Mine (Basin Property), Faraday Township, Bancroft District, Hastings Co., Ontario, Canada xl=2.1cm wide	© Jay Vonderhey

Here we need to put general comments about Betafite specimens in general.


Betafite
Canada
Ontario, Hastings Co., Bancroft District, Faraday Township, Silver Crater Mine (Basin Property)

Betafite crystal, 4cm wide	© Rob Lavinsky

Betafite, 2.3 cm wide	© 2002 John H. Betts

Betafite, 2.3 cm wide	© 2001 John H. Betts

Betafite, 7cm wide	© Joseph A. Freilich

Betafite, 2cm wide	© Jay Vonderhey

Betafite, 4.5 cm wide	© Joseph A. Freilich

I don't know if any of you read an old reporting I did on Silver Crater, but back about 43 years ago, I was there collecting on a Gemboree arranged field trip, and the widow of the original owner had had the basin scraped to bedrock basically, by a dozer, and we went in there with a fresh slate. A lady american mineral dealer, and a couple from Burlington Ontario both found circular holes filled with black muck very near the center. They started digging before lunch and at around 4 they had both mined out the u-shaped tube to the bottom. The results were about 5x5 foot trestle tables covered with crystals of Betafites for the Burlington couple and a large wheel barrow filled to the brim for the lady dealer...and these were all free floaters ranging from pea sized to 3" and larger perfect singles and multiples...all nicely protected and preserved by that awful black mire. The lady mineral dealer when I asked her what she felt she had in specimens, stated that maybe about 100 thousand would be fair market value, and this was back in the 60's . I have never seen such a haul before or since, with the exception of the pit in St Hilaire that produced those spectacular serandites, or maybe the collecting of garnets at River Valley near N. Bay, Ontario. I always wondered what became of all those hundreds of Betafites...
[Ray Hill 2009]

When we collected there back in the 90's you paid $2. to cross the property, and the road to the mine was nicely marked with little arrows to follow as it wound through the woods back at least 1/2 mile to the mine. We were able at that time to drive right up on to the hill which is basically soild calcite. We parked up over where the adit goes under the hill. The reddish haloes do surround the areas where the mose betafites are found, but this is hard to see on the surface. It's mush easier to see what is going on by going into the adit and looking at the calcite there. The adit goes straight into the calcite body for a few feet, then there is a "crossroad" to the left and right, with a drift going up into the calcite. Looking at the walls in there you can see how the betafites cluster in zones. There isn't really anything to work inside the mine. I'm telling you this to save you the trouble of going in yourself, because God only knows how much radon there is in there. I spent as little time as possible and got out to work outside. On our first trip we tried to break up the calcite and found a few betafites, small ones up to a half inch or so, and some apatite, biotite, and hornblende crystals. The betafites are very brittle and easy to break, most of the time when you break the calcite you come up with two pieces, each with a half of the betafite crystal. On our second trip we had some good success by finding where there were betafites occurring and bringing home big chunks to toss in come acid in hopes that there were more crystals inside. Occasionally the betafites will pop out whole if you're lucky. My advice if you go is to try to break off big chunks if you can and bust them up. We found crystals up to 2 inches and clusters up to 4 inches, and only spent one day working at it. I'd love to get back there one day and give it another go. And by the way I wold be extremely surprised if it was all mined out. The calcite body is massive, and from what I saw it looks like the betafites go all through it.
[Jay Vonderhey 2009]



Now we need someone to finish the article.



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Tue, 28 Dec 2010 17:12:46 +0000 http://www.mindat.org/forum.php?read,67,151527,151527#msg-151527 http://www.mindat.org/forum.php?read,67,151527,151527#msg-151527 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities? After each set of pictures there should be some descriptive text. If none appears it means that we need someone to tell us about the specimens from that locality and something about the geology of the occurrence.



Boracite
Mg₃[Cl|B₇O₁₃]

BORACITE, Kalkberg hill, Lüneburg, Lower Saxony, Germany, 8mm wide	© Volker Betz

Boracite was first described, from Lüneburg, Germany, by Lasius in 1787 as "cubic quartz" - an understandable mistake considering that the science of mineralogy was still in its infancy, that the element boron had not yet been discovered, and that boracite had certain physical properties close to that of quartz (vitreous luster, lack of cleavage, and a hardness that actually slightly exceeds that of quartz). Within a year or two after its original discovery, mineralogists realized that it couldn't be quartz because the chemistry was different, although the full composition (magnesium chloro-borate) was not recognized until 1850!


Boracite
Bolivia
Cochabamba Department, Chapare Province, Alto Chapare District,

Boracite 6.8 cm wide	© Rob Lavinsky

Boracite on matrix 4.7cm wide	© Rob Lavinsky

Boracite on matrix 7cm wide	© Rob Lavinsky

Boracite crystal 1.3cm wide	© Rob Lavinsky

The eroded and slightly metamorphosed Cambrian or Precambrian saltdome caprocks exposed over several square kilometres of rainforest in the Alto Chapare region have become a prolific source of boracite. In the early 1940s, while investigating this then still roadless jungle for its asbestos deposits, Dr. Federico Ahlfeld found a solitary loose green cube in stream sand and sent it to Dr. Roberto Herzenberg, who destroyed it for wet chemical analysis. That remained the only known boracite crystal from the continent of South America for the next 50 years, until the early 1990s when the locality was rediscovered by Alfredo Petrov. Boracites here occur in many colours, mostly pale pastel shades (colourless, green, orange, pink, grey, exceptionally yellow); several crystal habits, most commonly pseudocubic, but also tetrahedral, and rounded combined forms; and in size range from microscopic up to the largest known crystals in the world (3.7cm). Typical pale green opaque to translucent cubes in the 1cm size range are so abundant that they should be readily available for less than $20. Aesthetic crystals around 1.5cm or more, or of colours other than light greenish, are hard to get and can be expected to cost a few hundred $$. Note that this is one of very few places in the world where boracite can be found on the surface, as opposed to underground in salt mines.


France
Luneville

There is no boracite here, although the locality has been mentioned several times in the paper literature as a boracite locality. Was probably originally a confusion with the name of the type locality - Luneburg - which has been uncritically copied as a boracite locality by several subsequent authors. Obviously shouldn't be included in a "best minerals" list, but we include this note just as a warning for future compilers of regional species lists.


Germany
Lower Saxony, Elze, Eime

Boracite on matrix 2.0 cm wide	© Rob Lavinsky

Germany
Lower Saxony, Hanover, Lehrte

Massive Boracite var. stassfurtite 3 cm wide	© Arliguie M

Germany
Lower Saxony, Lüneburg, Kalkberg Hill

Boracite crystal 5mm wide	© Volker Betz

Boracite crystal 8mm wide	© Volker Betz

Pseudocubic Boracite crystal 6mm wide	© Volker Betz

A 1cm tetrahedral Boracite crystal on matrix	© Peter Haas

Boracite crystal 1cm wide	© Rob Lavinsky

Boracite crystals largest ~7mm	© Jakub Jirásek

Lasius, G.S.O. (1787) Chemischen Annalen für die Freunde der Naturlehre, Arzneygelahrtheit, Haushaltungskunst und Manufacturen (Chemical Annals for the Friends of Natural History, Pharmacology, Home Economics and Manufacturing), #2, 333-336. - This publication constitutes the first description of boracite (then as "cubic quartz" ), making Lüneburg its type locality. The crystals immediately became a popular collectible, both among mineral collectors and among children who used them as dice, and they were even collected (and sold) by criminals who had been sent as punishment to labour in the gypsum quarry.
The largest crystals known from the type locality reached 3 cm size, but have since been lost. The largest currently preserved measures 1.7cm and is in a Lüneburg museum. It is no longer allowed to collect at the locality, but small crystals (2 to 5 mm) are often available on the market when old collections are recycled. Crystals of 1cm or more size are very rarely offered for sale.


Germany
Saxony-Anhalt, Bernburg

3mm pseudocubic Boracite xl on matrix	© JBS 2006

Boracite FOV 3mm	© O. Dziallas

Boracite FOV 1.1cm	© 2007 M. Kampf

Boracite FOV 1.2cm	© Peter Haas

Germany
Saxony-Anhalt, Stassfurt Potash deposit, Stassfurt

Boracite 8mm wide	© Volker Betz

Germany
Thuringia, Sondershausen, Glückauf Mine

Boracite crystal FOV 6mm	© 2006 M. Kampf

Poland
Kujawsko-Pomorskie, Inowrocław

Boracite 4mm wide	© E. Szełęg

United Kingdom
England, North Yorkshire, Loftus, Boulby Mine

© Rob Lavinsky

© Rob Lavinsky

© Knut Eldjarn

© Rob Lavinsky

USA
California, San Bernardino Co, Otis

"Boracite" was erroneously listed from here in a State publication in the 1930s, and this reference has appeared several times in the literature since then, uncritically copied by later authors. Was probably an error for borax or hydroboracite. Obviously shouldn't be included in a "best minerals" list, but we include this note just as a warning for future compilers of regional species lists.



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Alfredo Petrov Best Minerals B Fri, 11 Sep 2009 15:01:04 +0000 http://www.mindat.org/forum.php?read,67,143320,143320#msg-143320 http://www.mindat.org/forum.php?read,67,143320,143320#msg-143320 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Borax
Na₂[B₄O₇] · 10H₂O monoclinic

1.Borax crystals, Boron, California, USA ~7cm across	©

Borax crystals are likely to be found anywhere borate rich water from hot springs accumulates on the surface of the earth. As the water evaporates, eventually the water becomes saturated and borax crystals will start to crystallize. When all the water evaporates, the Borax crystals will start to dehydrate, loose half their water and become a white mineral called Tincalconite. Because Borax will dehydrate under normal atmospheric conditions and Tincalconite is soluble, these minerals are not very stable and often end up as piles of white powder in collection drawers. They can be preserved in their original state if extraordinary measures are taken. This means the creation of air and moisture tight containers where the humidity and temperature is kept constant. Usually it is much more trouble than it is worth.

Borax has been know for centuries and was originally imported into Europe from Tibet where it was prised as a flux by goldsmiths. Later, large deposits of borates, mostly in the form of Colemanite and Ulexite were found near the end of the 19th century in the USA, most notably in Death Valley, California. This was refined without too much trouble into borax and what ever other borates that were needed. Eventually a big deposit of crystallized borax was discovered at Boron, California and it became cheap enough that it could be offered for sale profitably as a water softening agent. Subsequent to the discovery of crystallized Borax at Boron, a huge deposit of borax was found in Turkey that is reported to be perhaps ten times the size of the one at Boron. It is likely that more deposits containing borax will also be found.
[Rock Currier 2009]


Borax
Argentina
Jujuy, Coranzuli, Loma Blanca borate deposit

2.Borax, ~8 cm maximum dimension	© Marcelo Olsina

Possibly there is some real borax in theses specimens, but more than likely it has all been dehydrated and altered to Tincalconite. We need someone to tell us about this deposit and the Borax specimens found there.


Borax
Italy
Tuscany, Pisa Province, Pomarance, Larderello

3.Borax crystal on matrix ~1.5cm	© Marco Barsanti

The Borax crystal in this picture has just begun to alter to Tincalconite but is mostly still Borax. We need someone to tell us about this locality and the Borax crystals it produces.


Borax
USA
California, Kern Co., Kramer District, boron, U.S. Borax Open Pit Mine

4.Borax xls growing on wood ~15cm wide	©

5.Borax crystals ~30 cm wide	©

5.Borax crystals ~15cm wide	©

7.Borax crystals ~12cm tall	©

8.Borax altering to Tincalconite ~12cm wide	©

9.Borax crystals, "hemimorphic" ~5cm wide	© JSS

Many of the specimens pictured above were taken yeas ago, shortly after they were collected. Certainly they have now altered to white opaque specimens of Tincalconite after Borax. They are all from the old underground mine at Boron, California. These crystals, to some people, are not real minerals, because man had a hand in creating them. These specimens and many more are found growing in sumps and partially flooded stopes in the old underground workings at Boron. Conditions in the underground mine, like most mines, is very stable and the temperatures rarely fluctuate more than a degree or two year round. This provides an ideal setting for the growth of well formed large crystals (crystals of more than 30 cm diameter are known) as the borax saturated water slowly evaporates. Crystals of several different morphologies are found at different places in the mine ranging for prismatic crystals like shown in pictures # 1 & 2 above. Sometimes the crystals are flat and tabular or big and blocky. Somtemes they are bladed and pointed like #9, although this is not a particularly fine example of this type of specimen. Anything that is thrown or falls into the borax saturated water will provide a handy matrix upon which crystals will form. Picture 4 shows a beautiful cluster of prismatic Borax crystals growing on some wood. Sometimes the crystals are almost white and colorless, but often slight impurities impart an amber color to the crystals. Upon exposure to air, they eventually all turn white. Picture 8 shows a Borax specimen in the process of altering to Tincalconite. Borax saturated water outside of the stable conditions of the underground mine sometimes produce borax crystals as they evaporate, but because of the daily fluctuating temperatures, the crystals are usually not well formed or very large.

At one time the underground mine at Boron was the largest underground operation in California with more than 200 miles of underground tunnels and stopes. The underground mine accessed the ore body predominately through three shafts, the Old Baker shaft, the furthest east, the Jenifer shaft and the most western shaft the West Baker shaft. All of these shafts and mines with the same name were eventually all connected underground and all worked the same ore body. Most of the borax crystals that were produced from the underground were mostly from the West Bake mine though some were produced from the old Baker mine. Eventually because of economic considerations, it was decided to open pit the deposit. At various times, large quantities of Borax crystals from have been collected from the sumps and partially flooded stopes of the old underground mine. Sometimes the mining company permits the collecting of these borax crystals, especially to assist the local gem and mineral society for their yearly gem and mineral show and auction. The collecting of these specimens has to be among the easiest and most fun of all mineral collecting endeavors. Because of the large size of the underground tunnels at Boron, you can actually drive into the mine and right up to the stope or sump where the crystals are located. The procedure is to wide into the partially filled stope and start banging the specimens out. Usually the water is less than three feet deep and very transparent, at least initially until you stir up the dust that has accumulated on the bottom of the stope/pond. You can see the crystals lining the walls and bottom of the stope and growing on anything that has been thrown or fallen into the stope. A few taps with a chisel is usually enough to free the specimens from their matrix. You spend a lot more time walking these specimens back to the edge of the stope and wrapping them than you do collecting them. After the water gets turbid you have to feel around with your hands to locate the good specimens and free them from the walls etc. It is always exciting to pick them up out of the turbid water to see the latest treasure. The crystals and especially the broken edges of crystals are very sharp and you can cut yourself easily. However you generally don't feel it because the borax solution does not sting like salt water, and the borax solution seems to act like an antiseptic and the cuts rarely become infected. Some of these Borax specimens have been traded for fine specimens. One particular trade I recall I wish I had made was for a very fine Glove wulfenite specimen.

Here is an interesting description by mine geologist Joe Siefke who collected a lot of outstanding Borax specimens from the underground section of the mine at Boron: In 2001 I had an opportunity to collect (now) tincalconite specimens from the Baker mine "C" level stopes as Redpath miners were clearing out timber & metal in preparation for final closure. That episode definitely marked the close of underground collecting. In subsequent years, the mine conducted campaigns of deep ore pillar blasting to ensure safe pit bench operations. A couple of years after I collected the Baker crystals & groups, after they had turned thoroughly white, I 'stabilized' the specimens by immersion in a bath of pure S&F acryllic floor wax, following what Dave Eyre recommended. The specimens appear have held up quite well. Joe further commented in a subsequent email that Redpath is an international underground mine contractor (google: redpath). The specimen in the visitor center is approx. 20 in. in greatest dimension. I collected 200 tincalconite specimens, about half singles & half clusters. The singles range is 2" - 6"; mostly 'blocky'/ few thin pencils. The clusters are 2x2" to 6"x8". The clusters & large singles are bubble wrapped & stored in sealed rubbermaid trays.

The reason that the miners were cleaning out the timbers and metal is because the open pit mine was going to expand into that area of old underground mining and the company did not want mine timbers and metal to screw up their crushers and ore processing facilities. The reason for the subsequent drilling and blasting of that section of the mine is because they wanted to collapse the old working in this part of the mine, so that when the heavy equipment mining that area in the open pit would not suddenly collapse into old underground workings. This had happened in the past.



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Mon, 28 Sep 2009 12:24:52 +0000 http://www.mindat.org/forum.php?read,67,141266,141266#msg-141266 http://www.mindat.org/forum.php?read,67,141266,141266#msg-141266 Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?



Brannerite
(U⁴⁺,Ca)(Ti,Fe³⁺)₂O₆

Brannerite, Dieresis Mine, El Cabril, Sierra Albarrana, Córdoba, Andalusia, Spain 6.1cm tall	© Rob Lavinsky

The Handbook of Mineralogy says indistinct prismatic crystals up to 30 cm exist, but do not specify the locality. Also as indistinct prismatic crystals, some showing an orthogonal prism zone; more typically as rounded, detrital grains and pebbles and as irregular embedded grains and masses. Found as a primary mineral in granite pegmatite and in granitic gneiss: in silicified pebble conglomerates; in hydrothermal quartz and calcite veins.¹ The type material was taken from a gold placcer near the head of Kelly Gulch in western Custer County, Idaho as detrital crystals and grains.²
1. Handbook of Mineralogy, Anthony, Bideaux, Bladh, Nichols Vol.III, p.76
2. Palache, C., H. Berman, and C. Frondel (1944) Dana's system of mineralogy, 7th edition), v. I, 774-775.


Brannerite
Austria
Salzburg, Hohe Tauern Mts, Gastein valley, Böckstein, Naßfeld Valley

Brannerite FOV 3mm	© Stephan Wolfsried

Brannerite, FOV 2.5mm	© Stephan Wolfsried

We need for someone to tell us about the specimens from this locality


Brannerite
Spain
Andalusia, Córdoba, Hornachuelos, Sierra Albarrana, El Cabril, Dieresis Mine

Brannerite 6.1cm tall	© Joseph A. Freilich

This mine would appear to have produced by far the largest well formed crystals of Brannerite yet found to date, but we need someone to tell us about them, when they were found, how big they got and how many were found as well as something of the geology of the deposit, associated minerals and the history of the place. Was it in fact a mine?


Brannerite
Sweden
Västmanland, Lindesberg, Håkansboda

Brannerite? xls ~1cm polished section,	© Kjell Gatedal

We need someone to tell us more about these specimens and the locality. Apparently there are micro Arsenopyrites frequently found embedded in these crystals.


Brannerite
Switzerland
Ticino (Tessin), Riviera, Lodrino, Iragna

6mm Brannerite crystal in matrix	© D.Respino

This is what Graeser et al. (1998) in: Mineralienlexikon der Schweiz, Wepf (Basel), 579 pp. say about Brannerite:

"The most important finds of brannerite come from two neighbouring pegmatite veins in a quarry near Lodrino, TI: flattened prismatic crystals to 2 cm, completely metamict, black to brown-black, dull, with traces of yellowish uranium secondaries, associated with (among other minerals) smoky quartz, rutile, ilmenite, scheelite and molybdenite.

Other occurrences of brannerite: In the Lengenbach quarry, one single small brannerite crystal was found as an inclusion in sartorite: elongated crystal, 0.6 mm in length, only partially metamict, with fine expansion cracks. - Brannerite was also found as fine-grained inclusions in uranium minerals of the Mürtschenalp, GL, from the Weisstannen valley, SG, and from trun, GR."

All references to the locality near Lodrino talk about "a quarry near Lodrino", "a quarry between Iragna and Lodrino", "a quarry along the road leading from Lodrino to Iragna", or simply of "Lodrino" or "Iragna", with no mention of a specific quarry. If you look at the satellite view, you can barely make out two quarries that have now overlapped into a large single pit.

Unless we can obtain specific information from somebody who has collected there, we should leave the entry as it is.
Vandal King has a specimen labeled Ghisletta Quarry, Lodrino, Switzerland
[Peter Haas 2009]



Brannerite
USA
Colorado, Chaffee Co., Mt Antero

Brannerite in/on aquamarine 5.5cm wide	©

I would be happier about this specimen in the image above if it had had a proper analysis.


Brannerite
USA
Colorado, Chaffee Co., Nathrop, Upper Browns Creek area, California Mine

Brannerite, 2.1cm tall	© 0

I would like to know who did the ID work on this specimen.



Click here to view Best Minerals B and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals B Fri, 19 Oct 2012 10:53:09 +0000 http://www.mindat.org/forum.php?read,67,129387,129387#msg-129387 http://www.mindat.org/forum.php?read,67,129387,129387#msg-129387
Ideally what we want to know about each significant mineral from each locality is:

1. What is the largest crystal of the mineral that the locality has produced?
2. What do the best specimens from this locality look like and where can one be seen?
3. Does the locality produce a variety of different kinds of specimens of this species, and what do the best of each type look like and how many of them were found etc.
4. What are the associated minerals found with this species and what is its geological setting?
5. How abundant are these specimens and when were they found? A type locality? In other words, how rare are they.
6. How do they compare to other specimens of the same mineral from other localities?
7. How much is it worth. This should probably be optional, but in cases where specimens are worth thousands of dollars we should probably say something of the value of these things.
8. What kind of care and feeding do these specimens require? Are they delicate, radioactive, unstable, color changeable etc.?
9. Are the specimens commonly faked, and if so, how to tell if they are?
10. Are there any interesting stories relating to the collecting of these specimens or their discovery as a new mineral?

Of course this is in reality impractical, but if we keep these questions in mind, we will do a lot better job when writing about them.]]> Rock Currier Best Minerals B Fri, 06 Mar 2009 10:46:29 +0000