 | | Book |
| about 25 articles. Milan Novák (1952, Vyškov, Czech Republic) Head of the Department of Mineralogy, Petrology...published in Czech Republic by Granit, s. r. o., Ditinova 10. 150 00 Prague 5, Czech Republic E-mail: i...reproduction by Studio W G . Prague Printed in Czech Republic by Finidr. s. r. o., Český Tčšín 06/23/03/01...References 15 20 28 Mineralogical Regions Czech Republic (Milan Novák) Hungary (Sándor Szakáll) Poland...85 114 Descriptions of the Mineral Species Czech Republic (Milan Novák). Hungary (Sándor Szakáll), Poland |
| | Book |
| published in Czech Republic by Granit. s. r. o.. Dninova I0. 150 00 Prague 5. Czech Republic E-mail: in...reproduction by Studio VVG, Prague Printed in Czech Republic by F111idr. s. r. o.. Ce ky Tesin 06/23/03/0............................................. 3 1 Czech Re public (M ilan Novak) ........................................................... 127 Czec h Republic (Mi lan Novak). Hungary (Sandor Szakall), Po land......................................... 397 Czech Republic (Moravia) ................................ |
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| localities for good ilmenite crystals exist in the region (Brunet, I 977b ). NEW YORK Amity, Orange County...Mount Malosa, Chilwa alkaline province, Zomba district. "Illite" is the name of a series of incompletely...Discm•t•ries, /960--20/ 5 ONTARIO Bentley Lake Road occurrence, Faraday Township, Hastings County. In fall 1994...site which they called the Bentley Lake Road occurrence, south of Bancroft. Sharp, flattened rhombohedral...specimens have come from an unusual calcite vein-dike occurrence with an exposure very near, indeed on the property |
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| shown by some blue specimens. Key words: gems, fire opal, spectroscopic analyses, trace elements, play of...the discovery of opal in the Brazilian area has been reported, even if white noble opal has been apparently...since 1945 (Bittencourt Rosa 1990). A transparent opal with green olive nuance and with some translucent...early Eighties the first detailed indications of the most important Brazilian outcrop of precious opals have... Among others we recall: common opal, white noble opal and fire opal from Pedro II (Bittencourt Rosa 1990 |
 | | Report (issue) |
| Contents 4 Map: Notable Opal Localities 50 BY BRUCE PAUL GABER 6 The Opal Enigma: Science, History...and Pins Afire: Play of Color in Opal BY MAX WEIBEL Sparkling Opal in Ancient Bones: Precious Relics...vibrant with opal pattern and color. In this extreme close-up of a Lightning Ridge black opal, the field...approximately 3 mm wide. Opal courtesy Jenni Brammall BY ALEX RITCHIE 52 An Opal Glossary of Terms BY...BY SI AND ANN FRAZIER BY PETER HUBER 64 Opal from Mexico: Unsurpassed Fire BY JURGEN SCHUTZ 18 Perfect |
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| from different sources, vary? What causes the occurrence of varieties? Why do diamonds, unlike other precious...mining operations, production, and economy of the most important gem deposits-in some cases referring to...concept of the layout of the book, emphasizing the most important geological events leading to the formation...since next to dinosaurs, gemstones are among the most popular objects sought out by visitors to many of...the challenger was to a large extent correct. In most natural history museums gemstones are displayed |
| | Book |
| from different sources, vary? What causes the occurrence of varieties? Why do diamonds, unlike other precious...mining operations, production, and economy of the most important gem deposits-in some cases referring to...concept of the layout of the book, emphasizing the most important geological events leading to the formation...since next to dinosaurs, gemstones are among the most popular objects sought out by visitors to many of...the challenger was to a large extent correct. In most natural history museums gemstones are displayed |
 | | Book (volume) |
| gem mining up to date. Here, then, is the latest, most complete information on North America’s gemstones...from one or more diamond-bearing kimberlite bodies, most likely in Canada. Systematic large-scale mining...certain other areas, as around the Great Lakes region. Numerous small discoveries of gem materials took...others, and set them down in what I believe to be the most reliable accounts. In this process I was aided by...2. Map of amber deposits in eastern Dominican Republic........cceseesseceersereenes Figure 3. Map of |
 | | Book |
| Petrified Wood 131 Characteristics of Agates; Opal, Queen of the Gems; Petrified Wood; Commonly Occurring...Family Gemstones The Various Names and Forms of Agate Opal and Its Varieties Recommendations for Use of Polishing...gemstones, and minerals have always ranked among the most valued substances on earth and, in a multitude of...thirteen basic rock types. These included amber (most precious of the ancient gems), calcite, fluorspar...quartzite, rock crystal, amethyst, chrysoprase, opal, etc.), serpentine, and steatite (massive talc) |
 | | Journal (issue) |
| patient fossicker can find precious opal there when he has recognised the opal level. The site is several kilometres...directions and permission to visit the site. The opal occurrence is superficially similar to those in volcanic...volcanic host rocks in other parts of the world. The opal completely or partially fills some, but not a l...contain opal is not obvious. As with all opal deposits there is a small amount of precious opal exhibiting...and a lot more potch. The specimens of precious opal which I have seen were milky with fair color, and |
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| 99, pages 1488–1499, 2014 Australian sedimentary opal-A and its associated minerals: Implications for...The vast majority of precious opal on the world market comes from opal fields in the Great Artesian Basin...analyzed 20 opal-A samples from the Andamooka (South Australia) and Yowah (Queensland) precious opal fields...silica, the mineral assemblage, and the host rock. Opal-A consists of submicrometer-sized silica spheres...dominant late-stage mineralization leading to precious opal happened at acidic pH. Our findings indicate that |
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| treasures to be found in North America, are perhaps the most fascinating—and the least known. Valuable gemstone...Jewelers and gemologists will find the latest and most accurate gem-identification data under each species...attempted to assemble mainly those facts which should be most useful to the student, the collector and connoisseur...Gemstones, embraces those minerals furnishing the most treasured gems of commerce. The next chapter is...El Paso, Texas. Information on the Virgin Valley opal deposits was given by G. Keith Hodson of Scottsdale |
 | Nuriel, Perach, Miller, David M., Schmidt, Kevin M., Coble, Matthew A., Maher, Kate (2019) Ten-million years of activity within the Eastern California Shear Zone from U–Pb dating of fault-zone opal. Earth and Planetary Science Letters, 521. 37-45 doi:10.1016/j.epsl.2019.05.047 | Journal (article/letter/editorial) |
| California Shear Zone from U–Pb dating of fault-zone opal Perach Nuriel a,b,∗ , David M. Miller c , Kevin...online xxxx Editor: A. Yin Keywords: U–Pb SHRIMP opal fault dating Eastern California Shear Zone a b...fault activity based on U–Pb dating of fault-related opal from secondary fault segments within the Eastern...well-exposed faults at near-surface conditions suggest that opal formation is associated with high-magnitude earthquakes...constraints from massive and sheared syntectonic opal (n = 74) on related secondary faults from this study |
 | | Book |
| Appendices summarize the mathematics and chemistry that most rock and mineral collectors find helpful. 4-- ...Earths atmosphere about 2 ago. Human beings are the most intel¬ billion years ago, permitting the extensive...support of animal life. The present oxygen the most curious, whether or not they’re content (21 percent)...Earths’ crust, eight of them make up al¬ oceans. most 99 percent of the crustal rocks by The hydrologic...all water on Earth magnesium (Mg), 2.1 percent. Most min¬ (including that in your blood right now) |
| | Book |
| Appendices summa rize the mathematics and chemistry that most rock and mineral collectors find helpful. --------...1-luman beings are the most intelligent creatures on Earth, and are among the most curious, whether or not...(K), 2.6 percent; and magnesium (Mg), 2.1 percent. Most minerals contain silicon and oxygen, and are called...noncrystalline solids are often called minerals also. The most common minerals in the Earth's crust are the so-called...have been identified by professional mineralogists. Most minerals are co1npounds-molecules made of two or |
 | | Journal (issue) |
| new gemstone material that can also serve as the most convincing diamond substitute to date (see Figure...looking squarely into the top of a stone at the culet region; doubling is only seen when focusing deeper at...gemstone material in facets, but not in the culet region (here somewhat out of focus) because the view is...rhombohedral 15R ABCBACABACBCACB R3 ml etc. i. The most common polytype of moissanite in synthetic abrasive...material is 6H; 15R is the second and 4H the third most common polytype. The topic of this report is the |
 | | Book |
| represent excellence in natural history publishing. Most books in the PHalarope series are based on a nature...the earlier history, indeed the prehistory, of a region. Conglomerates speak of a time when high nearby...readers of all ages with the world in which we live. Most of us are so concerned with the business of making...identification may at times require special equipment that most of us do not have. Many minerals, however, may easily...guides on rocks and minerals are available, but most of them are too difficult for the general reader |
| | Book (volume) |
| gem 1nining up to date. Here, then, is the latest, most complete information on North America's gemstones...one or 1nore dia1nond-bearing kimberlite bodies, most likely in Canada. Systematic large-scale mining...certain other areas, as around the Great Lakes region. Numerous s1nall discoveries of gem materials took...others, and set them down in what I believe to be the most reliable accounts. In this process I was aided by... Map of amber deposits in eastern Do1ninican Republic.................................. 10 Figure |
 | | Book (edition) |
| judgment. These include all the common minerals and most of those of any special economic, geological, or...silicates are placed last. The silicates are the most difficult minerals and so they are reached after...the following crystalline minerals respectively, hematite, gibbsite, dahllite, halloysite and kaolinite...III there is an elementary discussion of the occurrence, This includes a brief descripand association...(Glass and Hydrocarbons) PART 413 III THE OCCURRENCE, ASSOCIATION, AND ORIGIN OF MINERALS A. General |
 | | Journal (issue) |
| ___________ pg. 267 271 Chrysoprase and Prase Opal from Haneti, Central Tanzania James E. Shigley,...characteristics of Tanzanian chrysoprase and green prase opal are revealed. 280 Demantoid from Val Malenco,...Chattanooga, Tennessee Jaroslav Hyr`śl Prague, Czech Republic Lore Kiefert Lucerne, Switzerland A. J. A...strong indicator of HPHT treatment. Concerning the occurrence of the “cage” effect in natural (untreated) diamonds...em corundum—ruby and sapphire—has been among the most coveted of colored stones for millennia, historically |
 | | Report (issue) |
| statements 212 Native elements 212 Graphite Occurrence 212 Alterations 21 2 The sulphides 212 ...marcasite 213 Occurrence 213 Alterations 214 216 fluorides Fluorite _ 216 Occurrence 216 Alterations...Alterations 216 The oxides 217 21 7 Quartz Occurrence 21 7 CONTENTS. MINERALS CHAPTER V. Section...Modifications 220 Tridymite Occurrence 220 Modifications 220 221 Opal Occurrence 221 Modifications 221...etc 222 Hematite group 223 Corundum, hematite, and ilmenite 223 Corundum 223 Occurrence 223 Alterations |
 | | Journal (article/letter/editorial) |
| in the most effective way. As conceptual targeting of potential sites at a province/district to regional...Background geology Though iron ore is one of the most economically important natural commodities, there...Proterozoic, converting the M–G to martite–microplaty hematite (M–mplH) ores with some residual goethite (Morris...phases of events within the Hamersley Province, most importantly of which is an initial hydrothermal...remaining iron oxides to martite and microplaty hematite, further removal of gangue material such as carbonates |
 | | Report (volume) |
| Leonite Lueneburgite Magnesite Opal Polyhalite General features Forms Occurrence Origin Optical properties...structure of polyhalite rock 28. Various modes of occurrence of polyhalite 29. Vertical growths of polyhalite... halite, hematite, kainite, kieserite, langbeinite, leonite, lueneburgite, magnesite, opal, polyhalite...on the American continent. Halite is by far the most abundant mineral disclosed in the cores and is followed...characteristic mineral associations and modes of occurrence. The minerals are described in alphabetic order |
 | | Journal (entire run) |
| shell on the front cover is from the Coober Pedy opal fields, South Australia. The 10-ounce gold crystal...Deposit, S.A. - W.R. Ryall and E.R. Segnit Precious Opal in the Warrumbungles - J.V. Sanders Lunar Minerals...CL. Morvell Lithiophorite from the Kalgoorlie District, Wes tern Australia -1. Ostwald That Elusive Stichtite...Stichtite - Keith Lancaster On the Genesis of Volcanic Opal at Houghlahan's Creek near Teven-Tintenbar, N.S...Pseudomalachite from Near Tottenham, N.S.W. - DH. McColl ---Occurrence of Ferrierite from the South Coast Area, New |
 | | Journal (issue) |
| the mechanical handling part of the design was the most difficult. By mechanical handling, I mean the delivery...Such an approach would use to full advantage that most versatile and adaptive of all information processors...the way of inclusions that was unexpected. T h e most a b u n d a n t inclusions present in samples from...the initial state of the chromium. Perhaps the two most likely possibilities are : (a) finely disseminated... Mn) it likewise seems that chromium is the one most readily accepted. It was a little disappointing |
