 | | 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) | | Crown of Blanche of Lancaster Black Spinel from Thailand Camera-Drone Gem Exploration Volume 37 / No....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...26–64 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 Spinel—A Gem Material from Bo Phloi, Thailand |  | | 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) | | 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...feldspar (sanidine), nepheline, zircon, hercynite-spinel series and magnetite-hercynite series. The ruby...chemistry, SEM-EDS, corundum, ruby, sapphire, Thailand, origin. 1. Introduction Sutherland et al. (1998a)...origin contain primary mineral inclusions of Mgrich spinel, sapphirine, fassaite and garnet. Sutthirat 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...likely correspond to submicroscopic inclusions of spinel, colombo-tantalite and zircons respectively. In...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...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) | | 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 ~ ~~ . •~..., ~ '.~ ,:~ , 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...greatly 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...syngenetic inclusions of columbite-group phases, zircon, spinel and rutile, some contain additional nepheline and...200–215 201 Fig. 1. Late Mesozoic to Cenozoic gem corundum occurrences and associated basaltic fields |  | | 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 (article/letter/editorial) | | include Fe,Cusulphide (low in Ni), cobalt-rich spinel, Th,Ce-rich phosphate and uraninite. The similar...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 |  | | 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. The basanite is the probable source of gem-quality zircon and sapphire mined from placer deposits...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 (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...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...that the genesis of some sapphires from Kanchanaburi, Thailand is directly related to the intrusion of |  | | 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 (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 |  | 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; |  | 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) | | Markedly, the sapphires show several micrometer thick spinel coronas at the contact with the host basalt, indicating...Carbonatite Introduction Sapphire and ruby are gem varieties of corundum (α-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 world’s largest gem corundum suppliers (e.g., Guo et al. 1996; Limtrakun |  | 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, |  | | 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 |  | | 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 (article/letter/editorial) | | A cobalt-rich spinel inclusion in a sapphire from Bo Ploi, Thailand JINGFENG Guo*, W. L. GRIFFIN+ AND...Cobalt-rich spinel is found as a ~ 200 ixm inclusion, together with a glassy phase, in a gem-quality blue...sapphire from Bo Ploi, Thailand. This is the first reported natural occurrence of such a spinel. Its composition...chromite. The compositional ranges for the cobalt-rich spinel, obtained using electron microprobe and proton...elements decrease in abundance from core to rim of the spinel while the other elements increase. Crystal chemical |  | | 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...31-ct pink sapphire, Sri Lanka; (12) 5.79-ct pink spinel, Pamir Mountains, USSR; (13) 10.15-ct pink topciz |  | | Journal (article/letter/editorial) | | zircon. Introduction SAPPHIRES and rubies are gem varieties of corundum (Al2O3) that have very ‘pure’... © 2017 The Mineralogical Society accompanying gem-quality zircon (e.g. Graham et al., 2008; Giuliani...between intraplate Cenozoic basalts (black areas) and gem corundum deposits (unfilled hexagons). Taken and...for volcanic provinces from Raymond et al. (2012). Gem deposits compiled from Sutherland and Abduriyim (2009)...studied. 1553 JACQUELINE WONG ET AL. TABLE 1. Gem fields and associated lava-fields of eastern Australia |  | | 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 |  | | Journal (issue) | | .......................................... 50 Thailand ................................................Enterprises, Thailand; Facets Show, Sri Lanka; Thai Gems and Jewelry Traders Association, Thailand; Hong Kong...Pandit, Tanzania Janet Ann Russell, Thailand Surasit Sriorathaikul, Thailand Edward Boehm, USA InColor is published...the amazing array of gems and gem people. Even for an experienced gemologist or gem dealer nowadays it...ICA Ambassadors, miners and members active in the gem trade all around the world, for working hard in gathering |
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Gem mines, Bo Phloi, Bo Phloi District, Kanchanaburi Province, Thailand