 | | Journal (article/letter/editorial) | | sapphire-zircon-magnetite xenolith from the Chanthaburi Gem Province, Thailand ROBERTR. COENRAADS The Gemmological Association...Mineral Resources, Rama 6 Road, Bangkok 10400, Thailand AND F. [.IN SUTHERLAND Division of Earth and...magnetite-bearing xenolith from Khao Wua, near Chanthaburi in Thailand, conclusively demonstrates a common origin for...magnetite found in alluvial deposits in the Chanthaburi gem fields. The original aluminium- and titanium-rich...zircons (2.57 ___0.20 Ma) from the Chanthaburi-Trat gem fields and within the potassium-argon ages of 0.44 |  | | Journal (issue) | | Franks, B.Sc., Ph.D., F.G.A. South Yorkshire & District Branch: J. L Platts, F.G.A. Examiners: E. A. Jobbins...Dt.Gemmol.Ges., 23, 3, 178-9. Webster, R. (1975): GemsâTheir Sources, Descriptions and Identification,...INTENSIVE YELLOW TSILAISITE (MANGANESE TOURMALINE) OF GEM QUALITY FROM ZAMBIA By Dr KARL SCHMETZER* and Prof...â Idar-Oberstein, West Germany ABSTRACT Transparent gem tourmalines with an intensive yellow coloration from...members of the series dravite-uvite. In both groups of gem tourmalines small amounts of iron, i.e., small percentages |  | | Journal (issue) | | Blanche of Lancaster Black Spinel from Thailand Camera-Drone Gem Exploration Volume 37 / No. 1 / 2020...Report 2019 | Gold Demand Trends 2019 | ID of Green Gems with Portable Instruments | The Journalâs Cumulative...| Maine (USA) Mineral & Gem Museum Gem Notes Hessonite from Kunar Province, Afghanistan | Olshanskyite...26â64 of this issue describes its history and the gems it contains, which consist of blue and pink sapphires...and Gem Materials By Karl Schmetzer and H. Albert Gilg Black SpinelâA Gem Material from Bo Phloi, Thailand |  | Yui, Tzen-Fu, Wu, Chao-Ming, Limtrakun, Phisit, Sricharn, Weerapan, Boonsoong, Apichet (2006) Oxygen isotope studies on placer sapphire and ruby in the Chanthaburi-Trat alkali basaltic gemfield, Thailand. Lithos, 86 (3) 197-211 doi:10.1016/j.lithos.2005.06.002 | Journal (article/letter/editorial) | | the Chanthaburi-Trat alkali basaltic gemfield, Thailand Tzen-Fu Yui a,*, Chao-Ming Wu b, Phisit Limtrakun...Science, Chiang Mai University, Chiang Mai 50200, Thailand Received 6 April 2005; accepted 8 June 2005 Available...(C-T) alkali basaltic gemfield in southeastern Thailand. Sapphires have O-isotope composition in the range...4.8x to +5.0x, demonstrating that the C-T placer gem corundums cannot be phenocrysts of these basalts...sub-continental mantle as the primary source for these placer gem corundums is tentatively proposed. The surface distribution |  | | Journal (issue) | | 7 July 2003 The Gemmological Association and Gem Testing Laboratory of Great Britain ~ ~~ . â˘~..., ~ '.~ ,:~ , Gemmological Association and Gem Testing Laboratory of Great Britain 27 Greville Street...(Figure 1) were purchased by a German gem merchant in northern Thailand and were said to originate from Myanmar...Myanmar by local dealers. During further trips to Thailand, our supplier was able to obtain some similar...photo by M. Glas. Š Gemmological Association and Gem Testing Laboratory of Great Britain ISSN: 1355-4565 |  | | Journal (article/letter/editorial) | | 92008, SC *aaron.palke@gia.edu Montana Bureau of Mines and Geology, Montana Tech, 1300 West Park Street...from their melt inclusions 59701 MA ABSTRACT Gem corundum (sapphire) has been mined from an ultramafic...recrystallized melt inclusions contain analcime and calcite drawing a striking resemblance to leucocratic ocelli...deposit in central Montana has produced exceptional gem- SC quality corundum (sapphire) for more than 100...lamprophyre-hosted sapphire deposit. However, the association of gem corundum (ruby and sapphire) with mafic, ultramafic |  | | Journal (issue) | | Association and Gem Testing Laboratory of Great Britain The Gemmological Association and Gem Testing Laboratory...3334 l Fax: +44 (0)20 7404 8843 e-mail: information@gem-a.info l Website: www.gem-a.info President: E A Jobbins...very likely also be Š Gemmological Association and Gem Testing Laboratory of Great Britain ISSN: 1355-4565...for alexandrite effect. Alexandrite effect (AE) Gem minerals changing colour between daylight and incandescent...first observed in a mineral found in the emerald mines at Tokowaia in the Urals (WĂśrth, 1842; Kokscharow |  | Graham, Ian, Sutherland, Lin, Zaw, Khin, Nechaev, Victor, Khanchuk, Alexander (2008) Advances in our understanding of the gem corundum deposits of the West Pacific continental margins intraplate basaltic fields. Ore Geology Reviews, 34 (1) 200-215 doi:10.1016/j.oregeorev.2008.04.006 | Journal (article/letter/editorial) | | g e o r ev Advances in our understanding of the gem corundum deposits of the West PaciďŹc continental...greatly increased our knowledge of the basalt-derived gem sapphireârubyâzircon deposits. In this paper we focus... We also critically review existing data on the gem corundum deposits, in order to further reďŹne a model...200â215 201 Fig. 1. Late Mesozoic to Cenozoic gem corundum occurrences and associated basaltic ďŹelds...a distance of over 12,000 km (Fig. 1). Although gem corundums occur within the present-day alluvial systems |  | | Journal (issue) | | have been known to produce district of the Northern Rift Valley Province, and corundum in all possible...northwards through the Sudan appeared on the Kenyan gem market of which and Ethiopia (Bridges, 1982). some...stretches from the turn off the never appeared on the gem market. main Lodwar road to the Sudan. This is a...and peneplanation of hills, namely bluish-green gems. Lower grade rough can be used Pelekesh (1794m)... is located in the Turkana district of the Northern Rift Valley Province on the west side of Lake Turkana |  | | Journal (issue) | | JOURNAL OF THE GEMOLOGICAL INSTITUTE OF AMERICA Gem Art of the Taj Mahal and the Mughal Era Characteristics...in Corundum from Bo Welu, Thailand Fall 2019 VOLUME 55, No. 3 EDITORIAL 293 Gem Art of the Taj Mahal...Chris L. Rogers, and Robert Weldon A look at the gem ornamentation of this landmark, as well as the jewels...in Ruby and Sapphire from the Bo Welu Gem Deposit in Chanthaburi, Thailand Supparat Promwongnan and Chakkaphan...and Color of Cultured Half-Pearls from Phuket, Thailand Kannika Kanjanachatree, Napapit Limsathapornkul |  | | Conference Proceedings | | term cultured pearl. Experts from various European gem testing laboratories were invited to attend a series...per country; this member being the Director of a Gem Testing Laboratory, or a gemmologist of the calibre...Stellenboch (1991), Paris, France (1993); Bangkok, Thailand (1995); Idar Oberstein, Germany (1997); Goa, India...Spain, Sri Lanka, Switzerland, Sweden, Tanzania, Thailand, U.S.A., Vietnam and Zimbabwe. During the 20th...14:40 Alessandra Costanzo , Martin Feely: Review gem-materials from Connemara, Western Ireland. 14:40 |  | | Journal (article/letter/editorial) | | terrains sparsely distributed in eastern Australia, Thailand and eastern China. The lack of understanding of...alluvial processes resulted in economic deposits of the gem-quality variety sapphire in eastern Australia, eastern...China, the Indochina region of southeastern Asia (Thailand, Vietnam and Cambodia) and northern Africa (Kenya...corundum crystals in basalts of the Hoy Volcanic Province in central Queensland, Australia. At two localities...abundance of xenoliths and of corundum (Fig. 1 a). The gem-quality corundum Fig. 1 a A deep blue corundum megacryst |  | Baldwin, L. C., Tomaschek, F., Ballhaus, C., Gerdes, A., Fonseca, R. O. C., Wirth, R., Geisler, T., Nagel, T. (2017) Petrogenesis of alkaline basalt-hosted sapphire megacrysts. Petrological and geochemical investigations of in situ sapphire occurrences from the Siebengebirge Volcanic Field, Germany. Contributions to Mineralogy and Petrology, 172 (6) doi:10.1007/s00410-017-1362-0 | Journal (article/letter/editorial) | | Carbonatite Introduction Sapphire and ruby are gem varieties of corundum (Îą-Al2O3) and belong to the...gemstones, along with diamond and emerald. Deposits of gem-quality corundum are well distributed around the...g., Hughes 1997). A review of the literature on gem corundum shows that corundum occurs in various geological...volcanism as these are among the worldâs largest gem corundum suppliers (e.g., Guo et al. 1996; Limtrakun...et al. 2015), while numerous corundum, including gem crystals, were recorded in extensive flows south |  | | Journal (issue) | | and G u o Jingfeng REGULAR FEATURES Gem Trade Lab Notes Gem News Book Reviews Gemological Abstracts...Pelt-Photographers, Los Angeles, CA. Typesetting for Gems & Gemology is by Scientific Composition, Los Angeles...Japanese translation of Gems o) Gemologx contact the Association of Japan Gem Trust, Okachimachi Cy Bldg...Taito-ku, Tokyo 110, Japan. MANUSCRIPT SUBMISSIONS Gems eJ Gemology welcomes the submission of articles...editor for a copy. Letters on articles published in Gems d Geniology and other relevant matters are also |  | | Report (issue) | | GEOLOGICAL SURVEY Geology and mineral deposits of Thailand by I/ D. R. Shawe Open-File Report 84- Prepared...Prepared on behalf of the Government of Thailand and the Agency for International Development, U.S. Department..................................... GEOLOGY OF THAILAND.................................................framework of the region surrounding Thailand..... Geologic history of Thailand............................................................................... Gem minerals........................................ |  | | Journal (issue) | | Phillips and Anatoly S. Talantsev Opal from Shewa Province, Ethiopia Mary L. Johnson, Robert C. Kammerling...and John I. Koivula REGULAR FEATURES Gem Trade Lab Notes Gem News Thank you, Donors Book Reviews Gemological...Guidelines for Authors ABOUT THE COVER: Perhaps no gem material in modern times carries the mystique of...Communist Russia, however, demantoids-like other gems-fell out of favor. With virtually no mining for...Pelt-Photographers, Los Angeles, CA. Color separations for Gems & Gemology are by Effective Graphics, Compton, CA |  | Giuliani, Gaston, Groat, Lee, Fallick, Anthony, Pignatelli, Isabella, Pardieu, Vincent (2020) Ruby Deposits: A Review and Geological Classification. Minerals, 10 (7) 597 doi:10.3390/min10070597 | Journal (article/letter/editorial) | | uncommon on Earth but the gem varieties of ruby and sapphire are relatively rare. Gem corundum deposits are...specifically Type IA where xenocrysts or xenoliths of gem ruby of metamorphic (sometimes magmatic) origin are...models; exploration 1. Introduction Ruby is the red gem variety of the mineral corundum. The name corundum...Rubyâ for gems mined from the modern-day Tajikistan (spinel), and âBohemian rubyâ was used for gems coming...science, but also about history, art, and trade, these gems are still called by their historic ârubyâ name, |  | Palke, Aaron C., Wong, Jacqueline, Verdel, Charles, Ăvila, JanaĂna N. (2018) A common origin for Thai/Cambodian rubies and blue and violet sapphires from Yogo Gulch, Montana, U.S.A.?. American Mineralogist, 103 (3) 469-479 doi:10.2138/am-2018-6164 | Journal (article/letter/editorial) | | with rubies from the Chantaburi-Trat region of Thailand and the Pailin region of Cambodia. The similarities...rubies and Yogo sapphires suggest a common origin for gem corundum from both deposits. Specifically, we advance...the lamprophyre or basalts that transported the gem corundum to the surface partially melted Al-rich...transported them to the surface. The similarities in these gem corundum deposits suggests that the partial melting...previously realized. Importantly, in both cases the gem corundum has an ostensibly âmetamorphicâ trace element |  | | Book | | r¡ Butterworths Gem Books Edited by Peter G. Read Amber Helen Fraquet Beryl John Sinkankas and Peter... Huddlestone Topaz D. B. Hoover Butterworths Gem Books Corundum Richard W. Hughes Executive Vice...Asian Institute of Gemological Sciences, Bangkok, Thailand Butterworth-Heinemann London Boston Singapore...Corundum/Richard W. Hughes. p. cm.-{Butterworths gem books) Bibliography: p. Includes index ISB!'i 0-7506-1006-9:...(colour swirls), etc. Major sources: Burma, Thailand, Cambodia, Sri Lanka, India, Australia, Kenya |  | | Journal (issue) | | EDITORIAL The 1980s in Review: New Realities of the Gem and Jewelry Industry Richard T Liddicoat and W i...Boyajian Thank You! Alice S. Keller FEATURE ARTICLES Gem Localities of the 1980s J a m e s E. Shigley, Dona... K o i v ~ ~ l a n, d Robert E. Kane Synthetic Gem Materials in the 1980s Kurt Nassau New Technologies...Misiorowski REGULAR FEATURES Gem Trade Lab Notes Gem News Most Valuable Article Award Gems & Gemology Challenge...PeltĂâPhotographers Los Angeles, C A . Typesetting for Gems &. Gernology i s b y Scientific Composition, Los |  | | Journal (article/letter/editorial) | | 8 cts and up to 200 cts), and quality, including gems, the U/P type dominates in Siberian kimberlites... concrete exposure to CO2 is known to lead to calcite formation, which partially inhibits further chemical...mineral precipitates consist of various forms of calcite and that there are significant differences in the...1st level of the Christiana 132 area, Kamariza Mines, Lavrion, East Attica, Greece. This mineral phase...DETERMINATION OF SULFATE INCORPORATION IN CALCITE, Mg-CALCITE AND ARAGONITE Goetschl, K.E.1, Mavromatis |  | | Journal (issue) | | Inclusions in Thai Rubies Gem Exploration in Canada Images Seen Through Calcite Volume 36 / No. 7 /...Presentations | Platinum Jewellery Business Review 2019 Gem Notes Albite from Brazil | Dark Blue Beryl from Pakistan...International Co. Ltd, Bangkok, Thailand, and the center and right rings are from Prima Gems, Bangkok). Photo by...Composition in Ruby from the Bo Rai Gem Field in Trat Province, Eastern Thailand By Supparat Promwongnan and...Differential Magnification of Images Seen Through Calcite and Other Uniaxial Materials By Harold Killingback |  | | Journal (issue) | | INSTITUTE OF AMERICA Geographic Origin Special Issue Gems & Gemology Journals, Charts and More Available Through...facing the gem and jewelry industry today. FEATURE ARTICLES 464 Geology of Corundum and Emerald Gem Deposits:...last two decades, knowledge of the formation of gem deposits has improved significantly. This article...state of our knowledge of the geology and genesis of gem corundum and emerald deposits. p. 569 512 A Review... Breeding, and Barbara L. Dutrow Copper-bearing gem tourmaline, known as ParaĂba tourmaline after the |  | | Journal (issue) | | low-temperature heat treatment on inclusions in this gem material, as well as the use of FTIR spectroscopy...evolution over the past 3.5 billion years. 542 Gem News International New emerald locality in Southern...Skalwold John I. Koivula Technical Editors Editors, Gem News Customer Service Tao Z. Hsu Emmanuel Fritsch...Tokyo, Japan Prague, Czech Republic Bangkok, Thailand Timothy Adams Dorrit Jacob Karl Schmetzer ...Prairie, Washington Maidenhead, UK Bangkok, Thailand Emmanuel Fritsch Ren Lu D. Brian Thompson |  | | Journal (issue) | | GEMS & GEMOLOGY SUMMER 2002 VOLUME XXXVIII SUMMER 2002 PAGES 123â204 Featuring: Characteristics and...description terminology used for pink diamonds on GIA Gem Trade Laboratory grading reports. pg. 129 NOTES...identified as color treated. REGULAR FEATURES 161 Gem Trade Lab Notes ⢠Aurichalcite cabochon ⢠Another...Cobalt-âdiffusedâ sapphire ⢠Schlossmacherite beads 170 Gem News International ⢠Conference reports ⢠New round...CA 92008 (760) 603-4504 akeller@gia.edu Editors, Gem Trade Lab Notes Thomas M. Moses, Ilene Reinitz, Shane |
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