| | 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 (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... The sapphire suite includes alkali feldspar (sanidine), nepheline, zircon, hercynite-spinel series and...chemistry, SEM-EDS, corundum, ruby, sapphire, Thailand, origin. 1. Introduction Sutherland et al. (1998a)...conditions of the genesis of the host ruby from eastern Thailand. Garland et al. (2001) in a study of Montana sapphires | | | 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 Journalās Cumulative...| Maine (USA) Mineral & Gem Museum Gem Notes Hessonite from Kunar Province, Afghanistan | Olshanskyite...26ā64 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 SpinelāA 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): GemsāTheir Sources, Descriptions and Identification,...INTENSIVE YELLOW TSILAISITE (MANGANESE TOURMALINE) OF GEM QUALITY FROM ZAMBIA By Dr KARL SCHMETZER* and Prof...ā 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 | | 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...Laos) Blue Bluegreen 1 ā Chantaburi (Thailand) 4 ā Bo Phloi (Thailand) 5 ā Hainan 6 ā Fudjian 7 ā Shandong...(S Laos) 1.3 1.3 1 ā Chantaburi (Thailand) 1.8 4 ā Bo Phloi (Thailand) b.d.l. 5 ā Hainan 6 ā Fudjian 1 | | | Journal (issue) | 7 July 2003 The Gemmological Association and Gem Testing Laboratory of Great Britain ~ ~~ . ā¢~..., ~ '.~ ,:~ , 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. Ā© Gemmological Association and Gem Testing Laboratory of Great Britain ISSN: 1355-4565 | | | 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 | | 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 Paciļ¬c continental...greatly increased our knowledge of the basalt-derived gem sapphireārubyāzircon deposits. In this paper we focus... We also critically review existing data on the gem corundum deposits, in order to further reļ¬ne a model...200ā215 201 Fig. 1. Late Mesozoic to Cenozoic gem corundum occurrences and associated basaltic ļ¬elds...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 | | | 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 Ā© 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 (Wƶrth, 1842; Kokscharow | | 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 (Ī±-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 worldās 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 | | | Report (issue) | Distribution of volcanic features in Longwan district (listing 6) of Manchuria. Modified after Ogura...volcanic features (filled circles) in Qixingshan district (listing 10) of Manchuria. Shuangliao is a city...Wudalianchi (five connected lakes) district (listing 20) of Heilongjiang Province, northeastern China. Lakes...interpretation of volcanic features of Hsing-an (Xingan) district (listing 28) of Manchuria and Mongolia. (Modified...Teng-yueh (Tengchong). The volcanic rocks of this district were divided into three distinct groups: an early | | | Journal (article/letter/editorial) | cobalt-rich spinel inclusion in a sapphire from Bo Ploi, Thailand JINGFENG Guo*, W. L. GRIFFIN+ AND S. Y. O'REILLY*...with a glassy phase, in a gem-quality blue sapphire from Bo Ploi, Thailand. This is the first reported...corundum, sapphire, megacryst, alkali basalt, Thailand Introdnction INCLUSIONS of one mineral in another...xenocrysts in volcanic rocks. Earlier investigations of gem-quality corundum (sapphire and ruby) have shown that...(over 30 species) are present as inclusions but each gem-field tends to give different inclusion combinations | | | Journal (article/letter/editorial) | Chemical Composition of Penglai Sapphire in Hainan Province, China Guang-Ya Wang 1,2 , Xiao-Yan Yu 1,2, *...those of African sapphires. Sapphire in Hainan Province, China. Minerals 2022, 12, 832. https:// Keywords:...creativecommons.org/licenses/by/ 4.0/). 1. Introduction Gem-grade corundum is also known as sapphire and ruby...Penglai deposit in Hainan Province is one of the most important sapphire mines in China [10,11]. It lies...about 35 km2 . The Penglai sapphires in Hainan Province mainly occur in mafic volcanic rocks, including | | | 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 | | | Book | rĀ· 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) | 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 | | | Book | Gemstones Concentrated by Surface Waters: 1 5 The Gem Gravels of Sri Lanka 2. Gemstones Formed from Surface...Gemstones of Igneous-Hydrothermal Origin 3. Hydrothermal Gem Deposits: 35 39 The Emerald Deposits of Colombia...Colombia 4. Gemstones Formed in Pegmatites: 57 Gem Pegmatites of Minas Gerais, Brazil 5. Gemstones Formed...Rock: 71 The Ruby Deposits of Chanthaburi-Trat, Thailand PART III Gemstones Formed by Very High Temperatures...Gemstones Formed at Great Depths 8. Mantle Thrust Sheet Gem Deposits: 115 119 The Zabargad Island, Egypt, Peridot | | | Book | Gemstones Concentrated by Surface Waters: 1 5 The Gem Gravels of Sri Lanka 2. Gemstones Formed from Surface...Gemstones of Igneous-Hydrothermal Origin 3. Hydrothermal Gem Deposits: 35 39 The Emerald Deposits of Colombia...Colombia 4. Gemstones Formed in Pegmatites: 57 Gem Pegmatites of Minas Gerais, Brazil 5. Gemstones Formed...Rock: 71 The Ruby Deposits of Chanthaburi-Trat, Thailand PART III Gemstones Formed by Very High Temperatures...Gemstones Formed at Great Depths 8. Mantle Thrust Sheet Gem Deposits: 115 119 The Zabargad Island, Egypt, Peridot | | | 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 ParaĆba tourmaline after the | | Sutthirat, C., Saminpanya, S., Droop, G. T. R., Henderson, C. M. B., Manning, D. A. C. (2001) Clinopyroxene-corundum assemblages from alkali basalt and alluvium, eastern Thailand: constraints on the origin of Thai rubies. Mineralogical Magazine, 65 (2) 277-295 doi:10.1180/002646101550253 | Journal (article/letter/editorial) | assemblages from alkali basalt and alluvium, eastern Thailand: constraints on the origin of Thai rubies C. SUTTHIRAT1...Science, Chulalongkorn University, Bangkok 10330, Thailand ABSTR ACT An inclusion of corundum (ruby) was...lateCenozoic Chanthaburi-Trat volcanics of eastern Thailand. The clinopyroxene is fairly sodic, highly aluminous...clinopyroxene inclusions in rubies from nearby alluvial gem deposits, suggesting a common origin for the two...alkali basalt, Thailand, xenocryst. Introduction THAILAND is a world-famous source of gem corundum, including | | Sutherland, Frederick, Zaw, Khin, Meffre, Sebastien, Thompson, Jay, Goemann, Karsten, Thu, Kyaw, Nu, Than, Zin, Mazlinfalina, Harris, Stephen (2019) Diversity in Ruby Geochemistry and Its Inclusions: Intra- and Inter- Continental Comparisons from Myanmar and Eastern Australia. Minerals, 9 (1) 28 doi:10.3390/min9010028 | Journal (article/letter/editorial) | in the presence of lesser Cr contents. Numerous gem corundum-bearing sites are known in SE Asia, where...Mogok and Mong Hsu, Myanmar and East Australian gem regions involve the western Pacific continental margins...Geological Settings, Myanmar The corundum-bearing gem deposits in the Mogok area include both in situ and... and associated gem workings of the Mogok area, is shown in Figure 2. The Mogok gem stone tract at the...Myanmar and East Australian gem deposits, within the Figure Australian gem deposits, within the West Figure | | | Journal (article/letter/editorial) | zircon inclusions in sapphires from the Central Province, NSW. gives ages of 35.9+ 1.9 and 33.7_+2.1 million...49Ma for the timing of volcanism of the Central Province, NSW. These data, combined with the observation...presumably determines whether a particular basaltic province carries sufficient corundum to be worked into...uranium-lead dating, inclusions, zircon, Central Province, Australia. Introduction A LARGEnumber of important...associated with largely alkali volcanic terrains. The gem-quality corundum is commonly recovered, along with |
|