 | | Journal (article/letter/editorial) | | An unusual sapphire-zircon-magnetite xenolith from the Chanthaburi Gem Province, Thailand ROBERTR. COENRAADS...Mineral Resources, Rama 6 Road, Bangkok 10400, Thailand AND F. [.IN SUTHERLAND Division of Earth and...Abstract A sapphire, zircon and magnetite-bearing xenolith from Khao Wua, near Chanthaburi in Thailand, conclusively...origin for the sapphire, zircon and magnetite found in alluvial deposits in the Chanthaburi gem fields. The...zircons (2.57 ___0.20 Ma) from the Chanthaburi-Trat gem fields and within the potassium-argon ages of 0.44 |  | | 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 Journal’s Cumulative...| Maine (USA) Mineral & Gem Museum Gem Notes Hessonite from Kunar Province, Afghanistan | Olshanskyite...Emerald | Blue Sapphire with Partial Red Surface Diffusion | Glass-filled White Sapphire Cover photo:...26–64 of this issue describes its history and the gems it contains, which consist of blue and pink sapphires |  | | 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): Gems—Their Sources, Descriptions and Identification,...INTENSIVE YELLOW TSILAISITE (MANGANESE TOURMALINE) OF GEM QUALITY FROM ZAMBIA By Dr KARL SCHMETZER* and Prof...†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 (article/letter/editorial) | | online June 2011 Different origins of Thai area sapphire and ruby, derived from mineral inclusions and...Road, Khlong Toey Nua, Watthana, Bangkok 10110, Thailand *Corresponding author, e-mail: seriwat@hotmail...inclusions and coexisting minerals of gem corundum from the Thailand area analysed by SEM-EDS in this study...study can be divided into sapphire and ruby suites. The sapphire suite includes alkali feldspar (sanidine)...inclusion, chemistry, SEM-EDS, corundum, ruby, sapphire, Thailand, origin. 1. Introduction Sutherland et |  | Peucat, J.J., Ruffault, P., Fritsch, E., Bouhnik-Le Coz, M., Simonet, C., Lasnier, B. (2007) Ga/Mg ratio as a new geochemical tool to differentiate magmatic from metamorphic blue sapphires. Lithos, 98 (1) 261-274 doi:10.1016/j.lithos.2007.05.001 | Journal (article/letter/editorial) | | trace elements can act as the signature of a single gem-deposit as did oxygen isotope composition (Yui et...9000 ppm) and Ti (50 to 120 ppm). In Chantaburi (Thailand), sapphires are related to 3 My old alkali basalts...of Cr. In Bo Phloi (Thailand), the alluvial deposit is located 30 km north of Kanchanaburi and appears...al. / Lithos 98 (2007) 261–274 Magmatic blue sapphire from alkali basalts 1 — Pailin (Cambodia) 2 —...Laos) Blue Bluegreen 1 — Chantaburi (Thailand) 4 — Bo Phloi (Thailand) 5 — Hainan 6 — Fudjian 7 — Shandong |  | 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) | | studies on placer sapphire and ruby in the Chanthaburi-Trat alkali basaltic gemfield, Thailand Tzen-Fu Yui...Science, Chiang Mai University, Chiang Mai 50200, Thailand Received 6 April 2005; accepted 8 June 2005 Available...Available online 1 August 2005 Abstract Placer sapphire and ruby are common in the western zone and the...(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 |  | | Journal (issue) | | 7 July 2003 The Gemmological Association and Gem Testing Laboratory of Great Britain ~ ~~ . •~..., ~ '.~ ,:~ , 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. © Gemmological Association and Gem Testing Laboratory of Great Britain ISSN: 1355-4565 |  | 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 Pacific continental...Available online 3 June 2008 Keywords: Basalt Sapphire Ruby Zircon Continental margins West Pacific A...increased our knowledge of the basalt-derived gem sapphire–ruby–zircon deposits. In this paper we focus... We also critically review existing data on the gem corundum deposits, in order to further refine a model...200–215 201 Fig. 1. Late Mesozoic to Cenozoic gem corundum occurrences and associated basaltic fields |  | | Journal (issue) | | Telephone. n 467 J. Gemm., 1989,21,8 Star sapphire from Kenya N. R. Barot*, A. Flamini**, G. Graziani***...Lucerne, Switzerland well-shaped crystals. In the sapphire lots there are Abstract some pieces of dark brown...brown to black obsidian, Various cabochon-cut star sapphire samples from the brown zircon and translucent...basalts or in The world's main sources of star sapphire, up to secondary deposits (Bridges, 1982). this...are being picked up from produce and supply star sapphire. the large desert type sandy area in the NorthKenya |  | | Journal (article/letter/editorial) | | 92008, SC *aaron.palke@gia.edu Montana Bureau of Mines and Geology, Montana Tech, 1300 West Park Street...their melt inclusions 59701 MA ABSTRACT Gem corundum (sapphire) has been mined from an ultramafic lamprophyre...significant advancement in our understanding of sapphire genesis and sheds light on how mantle-derived...the surface. 1 ACCEPTED MANUSCRIPT Keywords: sapphire; corundum; melt inclusions; lamprophyre; liquid...Introduction The Yogo Gulch sapphire deposit in central Montana has produced exceptional gem- SC quality corundum |  | Piilonen, Paula, Sutherland, F., Danišík, Martin, Poirier, Glenn, Valley, John, Rowe, Ralph (2018) Zircon Xenocrysts from Cenozoic Alkaline Basalts of the Ratanakiri Volcanic Province (Cambodia), Southeast Asia—Trace Element Geochemistry, O-Hf Isotopic Composition, U-Pb and (U-Th)/He Geochronology—Revelations into the Underlying Lithospheric Mantle. Minerals, 8 (12) 556 doi:10.3390/min8120556 | Journal (article/letter/editorial) | | Cenozoic Alkaline Basalts of the Ratanakiri Volcanic Province (Cambodia), Article Southeastfrom Asia—Trace ElementBasalts...(U-Th)/He the Ratanakiri Volcanic Composition, Province (Cambodia), Geochronology—Revelations intoO-Hf...Zircon xenocrysts from alkali basalts in Ratanakiri Province, Cambodia represent a unique low-Hf zircon from...Abstract: Zircon xenocrysts alkali basalts Ratanakiri Province, Cambodia represent a unique low-Hf zircon ({100}...xenocryst; alkali basalt; Ratanakiri Volcanic Province; trace elements; O-isotopes and Hf-isotopes; U-Pb; |  | | 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 © 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 (Wörth, 1842; Kokscharow |  | | 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) | | testable. Introduction Most of the world’s current sapphire production is taken from recent or palaeo-alluvial...terrains sparsely distributed in eastern Australia, Thailand and eastern China. The lack of understanding of...relationship between the occurrence of alluvial sapphire deposits and the presence of basaltic rocks in...resulted in economic deposits of the gem-quality variety sapphire in eastern Australia, eastern China...China, the Indochina region of southeastern Asia (Thailand, Vietnam and Cambodia) and northern Africa (Kenya |  | | Journal (article/letter/editorial) | | AND GEOCHEMISTRY OF THE DENCHAI BASALT, NORTHERN THAILAND SANDRA M. BARR Department of Geology, Acadia University...northern Thailand is part of a large continental alkalic basaltic province extending through Thailand into...basanite is the probable source of gem-quality zircon and sapphire mined from placer deposits associated...f about 70 km 2 south o f Denchai in northern Thailand (Fig. 1). These basalts are part o f a large Late...Late Cenozoic continental basaltic province extending through Thailand, Kampuchea, Laos, and Vietnam. Petrologic |  | | 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...Inclusions in Ruby and Sapphire from the Bo Welu Gem Deposit in Chanthaburi, Thailand Supparat Promwongnan...and Color of Cultured Half-Pearls from Phuket, Thailand Kannika Kanjanachatree, Napapit Limsathapornkul |  | 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) | | basalt‑hosted sapphire megacrysts. Petrological and geochemical investigations of in situ sapphire occurrences...generally normative in corundum. Most of these sapphire occurrences are located in alluvial or eluvial...indicating chemical disequilibrium between the sapphire and the basaltic melt, supporting a xenogenetic...Columbite Group inclusion within one Siebengebirge sapphire using laser ablation–inductively coupled plasma–mass...indicates a close genetic relationship between sapphire crystallization and alkaline mafic volcanism in |  | | 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 |  | | 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:...Blue = sapphire All other colours are termed sapphire with the colour prefix (e.g. yellow sapphire) Phenomena: |  | | Journal (article/letter/editorial) | | tandfonline.com/loi/tigr20 Tectonic environments of sapphire and ruby revealed by a global oxygen isotope compilation...Charles Verdel (2017): Tectonic environments of sapphire and ruby revealed by a global oxygen isotope compilation...2017.1327373 ARTICLE Tectonic environments of sapphire and ruby revealed by a global oxygen isotope compilation...Brisbane, Australia ABSTRACT ARTICLE HISTORY Many sapphire and ruby occurrences are spatially linked with...(Al2O3) formation. We compiled a global data base of sapphire and ruby δ18O, from which the following major |  | | Journal (article/letter/editorial) | | pp. 1551–1576 Trace-element compositions of sapphire and ruby from the eastern Australian gemstone...(LA–ICP–MS) to measure trace-element concentrations in sapphire and ruby crystals from eight alluvial deposits...Tasmania, which is also within the gemstone belt. Our sapphire and ruby results reveal a continuum in trace-element...trace-element geochemistry, LA–ICP–MS, corundum, sapphire, ruby, eastern Australian gemstone belt, subduction... zircon. Introduction SAPPHIRES and rubies are gem varieties of corundum (Al2O3) that have very ‘pure’ |  | | 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...Ruby” for gems mined from the modern-day Tajikistan (spinel), and “Bohemian ruby” was used for gems coming...science, but also about history, art, and trade, these gems are still called by their historic “ruby” name, |  | Palke, Aaron C., Wong, Jacqueline, Verdel, Charles, Ávila, Janaína 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) | | proposed for volcanically transported ruby and sapphire deposits around the world. In this contribution...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 |  | | 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...(10) 4.82-ct emerald, Colombia; (11) 8.31-ct pink sapphire, Sri Lanka; (12) 5.79-ct pink spinel, Pamir Mountains |
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