| 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) | of formation: (Type I) magmatic-related and (Type II) metamorphic-related. Type I is characterized by...magmatic) origin are hosted by alkali basalts (Madagascar and others), and Type IB corresponding to xenocrysts...in kimberlite (Democratic Republic of Congo). Type II also has two sub-types; metamorphic deposits sensu...rubies from the recently discovered Didy mine in Madagascar also command high prices [19]. A set of eight...Ambohimandrosoa, Antsirabe area, cm2.1 × 1.3 andcm 1.7×cm 1 cm × 11.7cm) Antsirabe area, Madagascar. Collection: | | Garnier, V., Ohnenstetter, D., Giuliani, G., Fallick, A. E., Phan Trong, T., Hoà ng Quang, V., Pham Van, L., Schwarz, D. (2005) Basalt petrology, zircon ages and sapphire genesis from Dak Nong, southern Vietnam. Mineralogical Magazine, 69 (1) 21-38 doi:10.1180/0026461056910233 | Journal (article/letter/editorial) | erosional deposits in southeast Asia, Australia and Madagascar. The basalt ®elds yielding corundums are widespread...deposits of Dak Nong. The Dak Nong sapphire-mining district lies in the Dak Lak Province near the Cambodian...rocks sampled from basaltic ¯ows from the mining district of Dak Nong. Chemical analyses for the samples...trends. Feldspar microlites (Fig. 3) evolve from labradorite to andesine (An65.0 ÿ36.0) in the tholeiitic...Plagioclase phenocrysts (Fig. 3) show a restricted labradorite composition (An64.2ÿ51.1) with low Or content | | | Book | and kimberlite (IB) hosts. Metamorphic rocks (Type II) are subdivided into Metamorphic, sensu stricto,...Tanzania; Andilamena/Zahmena and Ampanihy/Toliara, Madagascar. Marble-ruby types included various deposits...sapphire deposits included Andilamena and Andrebabe, Madagascar; various Mogo Gem Tract sites, Myanmar; Elahera...Namehaca, Mozambique and Ampanihy and Zahmena, Madagascar. In contrast, Appaluttoq ruby, Greenland, 4...of formation: (Type I) magmatic-related and (Type II) metamorphic-related. Type I is characterized by | | Voudouris, Panagiotis, Mavrogonatos, Constantinos, Graham, Ian, Giuliani, Gaston, Melfos, Vasilios, Karampelas, Stefanos, Karantoni, Vilelmini, Wang, Kandy, Tarantola, Alexandre, Zaw, Khin, Meffre, Sebastien, Klemme, Stephan, Berndt, Jasper, Heidrich, Stefanie, Zaccarini, Federica, Fallick, Anthony, Tsortanidis, Maria, Lampridis, Andreas (2019) Gem Corundum Deposits of Greece: Geology, Mineralogy and Genesis. Minerals, 9 (1) 49 doi:10.3390/min9010049 | Journal (article/letter/editorial) | the Pan-African orogeny are present in southern Madagascar, East Africa, South India and Sri Lanka; those...sapphires occur in Australia, northern and central Madagascar, Nigeria, Cameroon, French Massif Central and...diaspore; 420 to 500 ◦ C (appearance of biotite) for zone II; 500 ◦ C to 540–580 ◦ C (disappearance of chloritoid)...consisting of of oligoclase/labradorite-orthoclase-muscovite oligoclase/labradorite-orthoclase-muscoviteand...metamorphism; (ii) syn-metamorphism depletion in O related to hydration subduction and metamorphism; (ii) syn-metamorphism | | | Journal (issue) | courtesy of Rio Tinto; (4) an 11.16 ct sapphire from Madagascar, GIA Collection no. 31618; (5) a 1.01 ct yellow...competitive rough diamond market. Political problems in Madagascar and a ban on gem exports from Myanmar disrupted...were combined under the jurisdiction of the U.S. District Court of New Jersey 168 PRODUCTION AND MARKETS...for gemstones. New Deposits and New Operations. Madagascar. Much of the global gem business for well over...in the middle of the decade was dominated by Madagascar. This was due in part to the Malagasy PRODUCTION | | | Journal (issue) | and Hope Diamonds . . . Opals from Ethiopia—and Madagascar Composite Turquoise . . . Microtomography of...114 New Occurrence of Fire Opal from Bemia, Madagascar Martina Simoni, Franca Caucia, Ilaria Adamo,...the proximity to San Diego’s historic pegmatite district, we will offer field trips to working gem mines...This pattern has been observed previously in type II diamonds, and studies suggest that the cell walls...in cathodoluminescence spectra and images of type II high-pressure synthetic diamond produced with high | | | Book | (Itabira), Colombia (Coscuez), Ethiopia (Shakisso), Madagascar (Mananjary), Russia (Ural mountains), Zambia...I: muscovite, tourmaline, albite, and quartz; Zone II: K-feldspar (microcline), quartz, and albite; Zone...medium-grained albite and quartz (Figure 3a–c); Zone II hosting homogeneous medium-grained K-feldspar (microcline)...between Zones II and III (Figure 3e,f), and spodumene and/or cassiterite in Zones I and II are common ([6]...microcline and quartz crystals collected from Zone II. Muscovite grains gathered from Zone I were suitable | | | Journal (article/letter/editorial) | rock composed almost entirely of plagioclase (labradorite to oligoclase) and little or no dark-colored...rock composed largely of the Ca plagioclase labradorite and hypersthene with olivine. A dense hard light-colored...phenocrysts of olivine and augite in a groundmass of labradorite, olivine, augite, and minor B–(E) leucite and...sediments but rarely in volcanic rocks e.g., Cobalt district of Ontario, Canada, Wittichen, Richelsdorf, Bieber...Jachymov, Czech Republic, Black Hawk District, USA, Batopilas District, Mexico (Fig. 04.01). These vein-type | | | Journal (article/letter/editorial) | rock composed almost entirely of plagioclase (labradorite to oligoclase) and little or no dark-colored...rock composed largely of the Ca plagioclase labradorite and hypersthene with olivine. A dense hard light-colored...phenocrysts of olivine and augite in a groundmass of labradorite, olivine, augite, and minor B–(E) leucite and...sediments but rarely in volcanic rocks e.g., Cobalt district of Ontario, Canada, Wittichen, Richelsdorf, Bieber...Jachymov, Czech Republic, Black Hawk District, USA, Batopilas District, Mexico (Fig. 04.01). These vein-type |
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