 | 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 Ă 1.3 andcm 1.7Ăcm 1 cm Ă 11.7cm) Antsirabe area, Madagascar. Collection: |  | Giuliani, Gaston, Fallick, Anthony, Rakotondrazafy, Michel, Ohnenstetter, Daniel, Andriamamonjy, Alfred, Ralantoarison, ThĂŠogène, 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...dâAntananarivo, Ambohitsaina, BP 906, Antananarivo 101, Madagascar Y. Offant Cerege, Europole MĂŠditerranĂŠen de lâArbois...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)...xenoliths contained in the alkali basalt of Soamiakatra have δ18O values ranging between 1.3 and 4.7â° |  | | 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 |  | | Journal (article/letter/editorial) | | East African rift (Krzemnicki et al. 1996), in Madagascar (Schwarz et al. 2000; Giuliani et al. 2007a)...Bras (δ18O=13.9â°). The ruby in the pargasite-anorthite amphibolite of Peygerolles in the Haut Allier...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 |  | 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 540â580 ⌠C (disappearance of chloritoid)...of phlogopite, anorthite, corundum, chlorite, zoisite, tourmaline and beryl. Anorthite crystals are composed...composed almost entirely of anorthite (98% An), while margarite can be found in places. According to Andriessen |  | 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 FiskenĂŚsset complex, Greenland. Lithos, 366. 105536pp. doi:10.1016/j.lithos.2020.105536 | Journal (article/letter/editorial) | | and anorthite, triggered by the intrusion of a 2.71 Ga pegmatite. Al is sourced from the anorthite reacting...ruby-forming reaction (Keulen et al. 2014b), and an anorthite-rich rock (anorthosite, leucogabbro). The reaction...(ortho-amphibole or cummingtonite), phlogopite, anorthite-rich Jo u plagioclase, cordierite, sapphirine...frequently, but are visible in several samples, as is anorthite (Figure 9D). Other less common minerals include:...that ruby was formed in a reaction between Pr anorthite-rich plagioclase in leucogabbro or anorthosite |  | 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) | | Australian Fields Weldborough1 mag. sapphire Anorthite, oligoclase, hercynite, chromite, zircon, molybdenite...blue sapphires from non-basaltic ďŹelds (Ilakaka, Madagascar; Ratnapura, Sri Lanka; Mogok, Myanmar) to those...isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin. Mineralium...1990. Liquidus phase relationships on the join anorthiteâ forsteriteâquartz at 20 kbar with applications...alkali feldspar xenocrysts in basaltic terranes. II. Geochemical and petrogenetic considerations. Canadian |  | | 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 3aâc); 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) | | and Hope Diamonds . . . Opals from Ethiopiaâand Madagascar Composite Turquoise . . . Microtomography of...114 New Occurrence of Fire Opal from Bemia, Madagascar Martina Simoni, Franca Caucia, Ilaria Adamo,...the proximity to San Diegoâs 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 |  | | Journal (issue) | | had to go on. GEMS & GEMOLOGY WINTER 2019 Madagascar are from metamorphic deposits, but the deposits...basaltsâtwo 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) | | Anglesite Anhydrite Anilite Ankerite Annabergite Anorthite (Ca end member plagioclase) Anothoclase Anthophyllite...are composed of Mg olivine, Ca and Cr pyroxene, anorthite and chromite. Spinifex texture is occurs in these...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...gemological products (Fig. 04.10). In the Marlborough district of Queensland, Australia, it occurs within the | | | Journal (article/letter/editorial) | | Anglesite Anhydrite Anilite Ankerite Annabergite Anorthite (Ca end member plagioclase) Anothoclase Anthophyllite...are composed of Mg olivine, Ca and Cr pyroxene, anorthite and chromite. Spinifex texture is occurs in these...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...gemological products (Fig. 04.10). In the Marlborough district of Queensland, Australia, it occurs within the |
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