 | Giuliani, Gaston, Fallick, Anthony, Rakotondrazafy, Michel, Ohnenstetter, Daniel, Andriamamonjy, Alfred, Ralantoarison, Théogène, Rakotosamizanany, Saholy, Razanatseheno, Marie, Offant, Yohann, Garnier, Virginie, Dunaigre, Christian, Schwarz, Dietmar, Mercier, Alain, Ratrimo, Voahangy, Ralison, Bruno (2007) Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin. Mineralium Deposita, 42 (3) 251-270 doi:10.1007/s00126-006-0105-3 | Journal (article/letter/editorial) | | isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin Gaston...d’Antananarivo, Ambohitsaina, BP 906, Antananarivo 101, Madagascar Y. Offant Cerege, Europole Méditerranéen de l’Arbois...Ambaranjana Antanimora, Antananarivo 101, Madagascar ces in Madagascar to provide a gemstone geological identification...characterization. Primary corundum deposits in Madagascar are hosted in magmatic (syenite and alkali basalt)...karsts. The oxygen isotopic ratios (18O/16O) of ruby and sapphire from primary deposits are a good indicator |  | | Journal (issue) | | courtesy of Rio Tinto; (4) an 11.16 ct sapphire from Madagascar, GIA Collection no. 31618; (5) a 1.01 ct yellow...collection, courtesy of Aurora Gems; (6) a 9.15 ct ruby from Winza, Tanzania, courtesy of Hakimi & Sons;...from other fields. Likewise, beryllium diffusion of ruby and sapphire brought together geologists, gemologists...competitive rough diamond market. Political problems in Madagascar and a ban on gem exports from Myanmar disrupted...disrupted supply channels for sapphire and ruby. And the proliferation of new sales avenues, through the Internet |
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