 | 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: |  | | 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 |  | Garnier, V., Ohnenstetter, D., Giuliani, G., Fallick, A. E., Phan Trong, T., Hoàng 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...plot in the diopside and salite ®eld of Poldervaart and Hess (1951) and in the diopside ®eld of Morimoto...in Ca (Wo up to 54.6%) and often lie above the diopside±hedenbergite join. The pyroxene pheno- The pyroxenes |  | | Journal (article/letter/editorial) | | East African rift (Krzemnicki et al. 1996), in Madagascar (Schwarz et al. 2000; Giuliani et al. 2007a)...inclusions are chromiferous spinel, aluminous diopside, and sapphirine. A consensus has yet to be found...Thailand (Sutthirat et al. 2001) or at Soamiakatra, Madagascar (Rakotosamizanany 2003). Rubies are generally...area such as in Cambodia (Pailin), Madagascar (Antanifotsy-Soamiakatra), Australia (Yarrowitch), and Thailand...basalts is found in central Madagascar (Rakotosamizanany 2003): the Soamiakatra deposit in the Antanifotsy |  | | 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,...CVD synthetic diamond over one carat • Synthetic diopside in manufactured glass • Green Be-diffused sapphire...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 |  | 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) | | partly kelyphitised pyrope garnet (40%), Al-rich diopside (30%) and unzoned Ca-plagioclase (30%), along...as random euhedra within the diopside. Based on the co-existing diopside-corundum pair and geothermal...Cr-spinel, spinel, sapphirine met. ruby High-Al diopside, pyrope, meionite, anatase mag.? sapphire Nepheline...and sapphirine dominate, whereas in the other Al-diopside and garnet dominate; this may suggest crystallization...of Sutthirat et al. (2001) for the co-existing diopside-corundum pair, along with geothermal gradient |  | Keulen, Nynke, Thomsen, Tonny B., Schumacher, John C., Poulsen, Majken D., Kalvig, Per, Vennemann, Torsten, Salimi, Rita (2020) Formation, origin and geographic typing of corundum (ruby and pink sapphire) from the Fiskenæsset complex, Greenland. Lithos, 366. 105536pp. doi:10.1016/j.lithos.2020.105536 | Journal (article/letter/editorial) | | group is corundum normative, and the other is diopside normative. Figure 3B shows the whole-rock compositions...Tanzania), the placer deposit of Andilamena (Madagascar), and to a lesser degree the metamorphic basaltic...ultramafic deposits like Winza, Tanzania and Ilalaka, Madagascar. Pr Again, this may reflect a similar history...– worldwide only rubies from Madagascar (Andilamena, Ilakaka, Soamiakatra, Iankaroka, Ambatomena) have...similar reported δ18 O ratios. Those deposits in Madagascar are Pr partially related to rocks with a similar |  | | 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 |  | | 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 (issue) | | had to go on. GEMS & GEMOLOGY WINTER 2019 Madagascar are from metamorphic deposits, but the deposits...basalts—two very different deposits, yet both from Madagascar. As stated earlier, when geographic origin determination...ring, courtesy of Ronald Ringsrud; a 7.04 ct Madagascar sapphire, courtesy of Mayer & Watt; and an exceptional...such as in Sri Lanka (Ratnapura, Elahera) and Madagascar (Ilakaka), produce the highest-quality sapphires...(Type I) and (2) tectonic-metamorphic-related (Type II). Several subtypes are defined and especially Type |  | | Journal (article/letter/editorial) | | Descloizite Diamond Diaspore Dietzeite Digenite Diopside Dioptase Djurleite Dolomite Donbassite Dumortierite...Silica-undersaturated basalt with normative nepheline, diopside and olivine but with no hypersthene. Lamprophyre...calcite. A metamorphic rock consisting mainly of diopside, wollastonite, Ca–Mg silicates which has derived...dominated by Mg olivine, Mg ilmenite, Cr pyrope, Cr diopside, phlogopite, enstatite and of Tipoor chromite...an ultramafic igneous rock consisting of augite, diopside, hypersthene, bronzite or enstatite. A Quartzite | | | Journal (article/letter/editorial) | | Descloizite Diamond Diaspore Dietzeite Digenite Diopside Dioptase Djurleite Dolomite Donbassite Dumortierite...Silica-undersaturated basalt with normative nepheline, diopside and olivine but with no hypersthene. Lamprophyre...calcite. A metamorphic rock consisting mainly of diopside, wollastonite, Ca–Mg silicates which has derived...dominated by Mg olivine, Mg ilmenite, Cr pyrope, Cr diopside, phlogopite, enstatite and of Tipoor chromite...an ultramafic igneous rock consisting of augite, diopside, hypersthene, bronzite or enstatite. A Quartzite |
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