http://www.mindat.org/msgboard-67.html Fri, 27 Nov 2009 09:50:13 +0000 Phorum 5.2.8-RC1 http://www.mindat.org/forum.php?read,67,158406,158415#msg-158415 http://www.mindat.org/forum.php?read,67,158406,158415#msg-158415 Rock Currier Best Minerals B Mon, 02 Nov 2009 11:58:58 +0000 http://www.mindat.org/forum.php?read,67,158406,158408#msg-158408 http://www.mindat.org/forum.php?read,67,158406,158408#msg-158408
Goethite ps after Pyrite. We've discussed this particular piece before, probably should be deleted.

Jolyon]]> Jolyon Ralph Best Minerals B Mon, 02 Nov 2009 11:22:57 +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
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	©

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.]]> Rock Currier Best Minerals B Mon, 02 Nov 2009 11:06:13 +0000 http://www.mindat.org/forum.php?read,67,143320,153410#msg-153410 http://www.mindat.org/forum.php?read,67,143320,153410#msg-153410 rockcurrier@cs.com. But before I do any negotiations I will need to know exactly who you are and what you want the images for.]]> Rock Currier Best Minerals B Mon, 28 Sep 2009 12:24:52 +0000 http://www.mindat.org/forum.php?read,67,143320,153407#msg-153407 http://www.mindat.org/forum.php?read,67,143320,153407#msg-153407
I would like to get a hold of you in order to negotiate the use of some photographic material from this page. how can i reach you? We have urgency since this is for a museum soon to be inaugurated.

thank you]]> jaime A. Best Minerals B Mon, 28 Sep 2009 11:50:21 +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


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	© Rob Lavinsky

© Rob Lavinsky

© Rob Lavinsky

Boracite 1.3cm	© Rob Lavinsky

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

1.0 cm crystal	© Rob Lavinsky

Lehrte, Hanover, Lower Saxony, Germany

3 cm massive "stassfurtite"	© Arliguie M

Kalkberg hill, Lüneburg, Lower Saxony, Germany

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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.



Bernburg, Saxony-Anhalt, Germany

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Stassfurt, Stassfurt Potash deposit, Saxony-Anhalt, Germany

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Thuringia, Sondershausen, Glückauf Mine

© 2006 M. Kampf

Poland
Kujawsko-Pomorskie, Inowrocław

© 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.]]> 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

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.]]> Rock Currier Best Minerals B Mon, 29 Jun 2009 19:59:36 +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


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	© Jim Hall 2009

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.]]> Rock Currier Best Minerals B Fri, 12 Jun 2009 08:49:32 +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