 | Nasdala, Lutz, Corfu, Fernando, Blaimauer, Doris, Chanmuang, Chutimun, Ruschel, Katja, Å koda, Radek, Wildner, Manfred, Wirth, Richard, Zeug, Manuela, Zoysa, E. Gamini (2017) Neoproterozoic amorphous āekaniteā (Ca2Th0.9U0.1Si8O20) from Okkampitiya, Sri Lanka: A metamict gemstone with excellent lead-retention performance. Geology, 45 (10) 919-922 doi:10.1130/g39334.1 | Journal (article/letter/editorial) | | Neoproterozoic amorphous āekaniteā (Ca2Th0.9U0.1Si8O20) from Okkampitiya, Sri Lanka: A metamict gemstone with...Company, No. 4, Gothami Mawatha, Mount Lavinia, Sri Lanka 1 2 ABSTRACT of a rather extreme example, the...form of āekaniteā from Okkampitiya, eastern Sri Lanka, has a chemical āekaniteā from Okkampitiya, southeastern...southeastern Sri composition of Ca2Th0.9U0.1Si8O20, corresponding to that of the tetragonal mineral ekanite. Lanka...(quotes are used herein to indicate that The Okkampitiya material, however, has undergone amorphization |  | | Report (issue) | | Ekanite Ca2 ThSi8 O20 c 2001 Ā° Mineral Data Publishing, version 1.2 Crystal Data: Tetragonal; may...09 100.3 97.5 100.00 (1) Eheliyagoda district, Sri Lanka. (2) Tombstone Mountains, Canada; by electron...O20 : (3) Ca2 ThSi8 O20 : Occurrence: Detrital (Sri Lanka); in a glacial erratic syenitic boulder (Tombstone...Distribution: From the Eheliyagoda and Okkampitiya districts, near Ratnapura, Sri Lanka. In the Tombstone Mountains...mineral's discoverer, F.L.D. Ekanayake, of Colombo, Sri Lanka. Type Material: Canadian Geological Survey, Ottawa |  | | Journal (issue) | | Diamonds from Guyana Surface Features of Ekanite from Sri Lanka A Study of Gems from Napoleon IIIās Crown...2 EDITORIAL 137 Diamonds from Guyana, Ekanite from Sri Lanka, a New Amber Source in Vietnam, and More...history and practices. p. 146 156 The Shape of Ekanite Lutz Nasdala, K.A. Geeth Sameera, G.W.A. Rohan...unusual surface characteristics of ekanite from secondary deposits in Sri Lanka. 168 A Gemological and Spectroscopic...ISSN 0016-626X Diamonds from Guyana, Ekanite from Sri Lanka, a New Amber Source in Vietnam, and More |  | | Conference Proceedings | | Henry A. HƤnni, Switzerland; Mr. Gamini Zoysa, Sri Lanka; Dr. Karl Schmetzer, Germany; Prof. Dr. Emmanuel...(1979), Kashiko-Jima, Japan (1981), Beruwela, Sri Lanka (1983); Sydney, Australia (1985); Rio de Janeiro...Norway, Russia, Singapore, South Africa, Spain, Sri Lanka, Switzerland, Sweden, Tanzania, Thailand, U.S...Chen Yanyu, ArÅ«nas KleiÅ”mantas: Spinels from Sri-Lanka. 11 36 th IGC 2019 ā Nantes, France Co nference...Chutimun Chanmuang N. , E. Gamini Zoysa : Ekanite from Sri-Lanka : what can we learn from a radioactive |  | | Journal (issue) | | April2000 2000 April ' SriLankan Lankan 'f^ ^ < Sri gemdeposits deposits ; . gem LW NwwTN Ā» ., GEPOL...deposits in in the the Okkampitiya Okkampitiya gem gem field, field, Sri Sri Lanka Lanka 1 1 2 V. V.Mathavan...University University ofofPeradeniya, Peradeniya,Sri SriLanka Lanka 2.2.Institutfur Institut fĆ¼r Geowissenschaften...discovered recently recently in inthe theOkkampitiya Okkampitiya gem gem field field which which isissituated...situated in in south-eastern south-eastern Sri Sri Lanka. Lanka. These These are are (1) (1) the the gem-bearing |  | | Journal (issue) | | iridescent chatoyancy Grey orthoclase moonstone from Sri Lanka has a unique combination of a cat's-eye and a...Brazil and another colourless of 12.20 ct from Sri Lanka, but this specimen is considerably larger. Two...Moonstone with a star and cat'seye combination from Sri Lanka Sunstone cat's-eye from Russia A stone described...purchased in Germany and probably comes from Sri Lanka, where a similar one was offered to the author...located 31.5 km south of the city of Wroclaw in the province of Dolny Slask (Lower southwest Poland (Figure |  | | Journal (article/letter/editorial) | | checked with several analyses of āekaniteā from Okkampitiya, Sri Lanka (207Pb/206Pb age = 562.1 Ā± 0.8 Ma;...assessment of monazite from the ItambĆ© pegmatite district for use as UāPb isotope reference material for...and Nakajima, T. (1983) Geology of the Iwakuni district. Quadrangle Series, Scale 1:50,000, Geological...garnet during prograde metamorphism from the Yanai district, Ryoke metamorphic belt, southwest Japan. Lithos...reactions of the Ryoke metamorphism in the Yanai district, southwest Japan: The formation of cordierite |  | | Journal (issue) | | in Colorless, Yellow, and Blue Sapphires from Sri Lanka Kcirl Scl~metzerand Olaf Medenbach REGULAR FEATURES...Banjarmasin-Martapura area of southeastern Kalimantan (the province of Kalimantan Selatan). The gemological characteristics...map shows the two major areas (left the Landak district of western Kali= man tan, below = the Bmjarn~asin-Maitapura...000 guilders worth of diamonds from the Landak district in what is now western Kalimantan. The 367-ct...Banjarmasin, the capital city of Kalimantan Selatan province. In GEMS & GEMOLOGY Summer 1988 this area |  | | Journal (issue) | | Scapolite with Unusual Properties from Embilipitiya, Sri Lanka Pieter C. Zwaan Some Tanzanite Imitations Lore...well-representedin this issue: Unusual gem materials from Sri Lanlza (a country Bob visited several years ago)...world gem market as the Ouro Preto Imperial topaz district comprises two major active mining sites-Cap50...operation is the Cap50 mine, in the Rodrigo Silva district. Specimens and information about that mine were...occurrence) on the west, both in the Ouro Preto district (again, see figure 2). Pires et al. (1983)identified |  | | Journal (issue) | | Number 2 TABLE OF CONTENTS FEATURE ARTICLES 62 Sri Lanka: The Gem Island Peter C. Zwnan The Identification...a n y fine gemstones found on the island o f Sri Lanka, the subject of Peter Zwaan's article i n this...this issue. This fine 9.57-ct cabochon from Sri Lanka is pictured here against a 19th century lithograph...not of the publishers. SRI LANKA: THE GEM ISLAND By Peter C. Zwaan Sri Lanka, formerly Ceylon, remains...mined by primitive methods. In many instances, the Sri Lankan origin of the gemstone can be determined by |  | | Journal (issue) | | 2010. Play-ofcolor opal from Wegel Tena, Wollo Province, Ethiopia. Gems & Gemology, 46(2), 90ā105, https://doi...had acquired more than 30 years ago from Okkampitiya, Sri Lanka. Of note was its strong, bright bluish...& b Figure 6: (a) This ālilacā spinel from Sri Lanka weighs 3.73 ct and measures 12.64 Ć 7.22 Ć 6.52...Tourmaline King Mine, Pala, California, USA The Pala District in San Diego County, California, USA, is famous...Gem- and Lithium-bearing Pegmatites of the Pala District, San Diego, California. Special Report 7-A, Division |  | | Book (edition) | | extensive fields in the prophetically named Kimberley district of Western Australia promise to be of world importance...cause raised eyebrows, and even more so with āSri Lanka rubies and sapphiresā in place of āCeylon rubies...intermediate and acid members of the volcanic province in southern Brazil and Uruguay, and the fire opals...is in such old river courses in countries like Sri Lanka and Thailand that the water-worn pebbles of many...particularly in the Yun Yang deposit in Hubei Province, China. For many years on the basis of experimental |  | | Journal (issue) | | Fuchsite Phantom Inclusions | Tourmaline from Sri Lanka with Transient Tenebrescence? | Diving for Natural...710ā725 of this issue) and therefore does not have a Sri Lankan origin as commonly described for Roman sapphires...Trapiche Ruby from Khoan Thong, Luc Yen Mining District, Northern Vietnam 726 By Isabella Pignatelli...an existing deposit such as those in the Karoi District or the Zambezi Valley (cf. www.mindat.org/ locentries...southern India (Eppler 1967, 1971), Ratnapura in Sri Lanka (Henn & Bank 1991) and more recently Norway (Schmitz |  | | Book | | pyrochlore) and zircon crystals are common in Sri Lanka gemstones. The more important syngenetic mineral...mica in andalusite, chrysoberyl, kornerupine and Sri Lanka sapphire ā¢ calcite in Burmese ruby and spinel;...andalusite ā¢ sphene in ruby and spinel ā¢ uraninite in Sri Lanka sapphire ā¢ zircon in corundum. Apatite is a characteristic...well seen in some green and brown zircon from Sri Lanka. The process is called āmetamictization and the...complex patterns, especially in sapphires from Sri Lanka. Burmese ruby contains short rutile needles, calcite |  | | Book (volume) | | Drosdov and A.P. Turinge 331 Gems deposits of Sri Lanka E. Gaminee Zoysa 343 Precious and semi-precious...formation were found in Mimecha-Kotui carbonatite province. This deposits are not mining yet for their difficult...modern quartz sand from iron in Pinar-del-Rio province, Cuba. Quartz sand places on the lowland derived...operation in Khingan brucite =magnesite= bearing province, Khabarovsk Territory, USSR. There are small brucitite...part in the Khingan brucite =magnesite= bearing province within Bureinskii old massif . The Amurskaya (presumably |  | | Journal (issue) | | field trip to the world-famous Pala pegmatite district in San Diego County will take place August 25...the market to the rarest collector gems, such as ekanite, taaffeite, axinite, and cassiterite. If a gemstone...sapphires from metamorphic rocks (e.g., from Sri Lanka) is completely different from that in sapphires...almandine with fibrous sillimanite from Okkampitiya, Sri Lanka; andalusite with sillimanite fibers from...(1968): Based on Dr. GĆ¼belinās numerous travels to Sri Lanka (formerly Ceylon), it provides information on |
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