 | | Book | | noted gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical...of the 'Irelawney Collection of the Los Angeles County Museum of Natural History. ♦ Figures vii Foreword...Tanzania 32 Sapphire from Kenya 42 Ruby from Mangari, Tsavo West National Park, Kenya 44 Chapter 4. Emerald...Red Dravite Tourmaline from the Narok District, Kenya 99 Uvite-Dravite Chrome Tourmaline 99 Chapter 8...Appendix B. East African Gemstones in the Los Angeles County Museum of Natmal History Collections 138 Appendix |  | | Journal (article/letter/editorial) | | Exotic origin of the ruby deposits of the Mangari area in SE Kenya A. Mercier a a,) , P. Debat a , John...of gem-corundum Ži.e., ruby and sapphire.. The ruby deposits in the Mangari area of SE Kenya, are among...dominated by sillimanite-graphitic gneisses, the Mangari deposits are associated with rootless ultrabasic...their margins. Field relationships reveal that the corundum-bearing rocks are genetically related to the ultrabasic...and pressures which did not exceed 7 kbar. At Mangari, the ruby-bearing rocks, as their associated ultrabasites |  | Sorokina, Elena S., Rösel, Delia, Häger, Tobias, Mertz-Kraus, Regina, Saul, John M. (2017) LA-ICP-MS U–Pb dating of rutile inclusions within corundum (ruby and sapphire): new constraints on the formation of corundum deposits along the Mozambique belt. Mineralium Deposita, 52 (5) 641-649 doi:10.1007/s00126-017-0732-x | Journal (article/letter/editorial) | | inclusions within corundum (ruby and sapphire): new constraints on the formation of corundum deposits along...Abstract Direct dating of corundum and the establishment of age constraints for corundum crystal growth are...mineral inclusions may help define minimum ages for corundum growth. Here, we present results of in situ LA-ICP-MS...LA-ICP-MS U–Pb dating applied to rutile inclusions in corundum from localities along the Mozambique belt. U–Pb...Ma for the Aqua Ruby mine, both in the Mangari area of Kenya, and an age of 499 ± 12 Ma for ruby from |  | | Journal (issue) | | alluvial gemstone than the ruby or sapphire. The corundum crystals of these gravels commonly display small...second order prisms and the bipyramid but not of a corundum Gemm., 1991,22,8 J. Gemm, 1991,22,8 467 crystal...are utilized here (Klaproth, 1801). Thus, on on corundum, or "oriental sapphire", sapphire'~ Klaproth disputes...identical to currently accepted analyses for for corundum. From and other comparisons with the the analyses...specific gravities, but but giving credit to CORUNDUM c(OOOI) SAPPHIRE RUBY 1200 ^=£s striated striated |  | Sorokina, Elena S., Hofmeister, Wolfgang, Häger, Tobias, Mertz-Kraus, Regina, Buhre, Stephan, Saul, John M. (2016) Morphological and chemical evolution of corundum (ruby and sapphire): Crystal ontogeny reconstructed by EMPA, LA-ICP-MS, and Cr3+Raman mapping. American Mineralogist, 101 (12) 2716-2722 doi:10.2138/am-2016-5614 | Journal (article/letter/editorial) | | 2016 Morphological and chemical evolution of corundum (ruby and sapphire): Crystal ontogeny reconstructed...natural corundum (rubies and sapphires), and the chemical and morphological evolution of corundum crystals...crystals from deposits in Africa (Kenya, Tanzania, Madagascar) and Southeast Asia (Vietnam). Trace-element...Trace-element compositions indicative for different corundum habits were determined by rim-to-rim LA-ICP-MS and electron...photoluminescence mapping. Results traced the development of corundum crystals and the evolution of their chemistry |  | | Book | | MINERALS& GEMSTONES of East Africa Burundi, Kenya, Rwanda, Tanzania and Uganda Bruce Cairncross Published...Africa 10 East African resources 12 Burundi 13 Kenya 14 Rwanda 16 Tanzania 17 Uganda 20 Gemological properties...through Tanzania, Kenya, Ethiopia and into the Sudan - has blessed East Africa, Kenya and Tanzania, with...now mainland Tanzania) and then progressing to Kenya - I am proud to say that the coloured gemstones...fact is that both of the national gemstones of Kenya and Tanzania (tsavorite and tanzanite, respectively) |  | | Journal (article/letter/editorial) | | Jmziiary 1,2999) Abstract Gem-variety of red corundum (i.e. ruby) is produced in the Ejeda-Fotadrevo...when Madagascar was still adjacent to East Africa (Kenya, Tanzania) in the Gondwanaland assembly at the end...East Africa, off the coast of southern Somalia, Kenya and Tanzania, to the east to southwestern India...seemed relatively poor in gem-corundum deposits compared with East Africa (Kenya,Tanzania),India and Sri Lanka...pre-breakup surrounding areas now famous for their gem-corundum wealth (ruby, sapphire) (Huglws, 1990; Menon et |  | Jacob, J.-B., Martelat, J.-E., Goncalves, P., Giuliani, G., Devidal, J.-L., Feneyrol, J., Omito, E., Ichang'I, D. (2018) New P-T-X conditions for the formation of gem tsavorite garnet in the Voi area (southwestern Kenya) Lithos, 320. 250-264 doi:10.1016/j.lithos.2018.09.010 | Journal (article/letter/editorial) | | tsavorite garnet in the Voi area (southwestern Kenya) J.-B. Jacob, J.-E. Martelat, P. Goncalves, G....tsavorite garnet in the Voi area (southwestern Kenya). Lithos (2018), doi:10.1016/ j.lithos.2018.09.010...tsavorite garnet in the Voi area (southwestern Kenya) J-B. Jacoba,*, J-E. Martelata,**, P. Goncalvesb...Mines and Geology Department Taita-Taveta, P.O. Box 1043-80304, Wundanyi, Kenya h M Department of Geology...Riverside drive, P.O. Box 30197-00100 GPO, Nairobi, Kenya Principal corresponding author ED *Corresponding |  | | Journal (issue) | | diffused red corundum normally displays a patchier colour than the equivalent diffused blue corundum. This...chromium atoms into the corundum than in diffusing the iron and titanium into corundum, which is used to obtain...obtain the more widely available blue diffused corundum. One of our members brought in some low quality...being faceted. 451 Figure 6: A diffused red corundum showing the typical patchy colour distribution...colour evident on some facets of a diffused red corundum. A white 'pearl' and a purplish grey /black 'pearl' |  | | Journal (article/letter/editorial) | | alexandrites as special cases), clinohumite, cordierite, corundum, danburite, diopside, ekanite (radioactive and...pallasite meteorites, gem benitoite from San Benito County California, and Colombian emeralds (for whose genesis...all; they are colour varieties of the mineral corundum when it is sufficiently transparent. In similar...that has been successfully used in prospecting in Kenya, Brazil, and no doubt elsewhere. Association with...from the Scorpion Mine (Mgama Ridge, southeast Kenya) could be mined with a teaspoon (Bridges 2007; Campbell |  | Wang, Kandy K., Graham, Ian T., Lay, Angela, Harris, Stephen J., Cohen, David Ronald, Voudouris, Panagiotis, Belousova, Elena, Giuliani, Gaston, Fallick, Anthony E., Greig, Alan (2017) The Origin of A New Pargasite-Schist Hosted Ruby Deposit From Paranesti, Northern Greece. The Canadian Mineralogist, 55 (4) 535-560 doi:10.3749/canmin.1700014 | Journal (article/letter/editorial) | | ICP-MS, XRF, and XRD have found the Paranesti corundum to be of a mafic/ultramafic protolith with approximately...analysis determined the mineral inclusions within the corundum grains to be picotite and hercynite spinels. Pargasite...amphibole within the corundum-bearing amphibole schist host. The surrounding non-corundum bearing chlorite...examination of the mineral assemblages within the corundum-bearing schists revealed strong fracturing and...the corundum grains and margarite reaction rims around the corundum. The surrounding non-corundum amphibolites |  | 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) | | minerals Article Gem Corundum Deposits of Greece: Geology, Mineralogy and Genesis Panagiotis Voudouris... Abstract: Greece contains several gem corundum deposits set within diverse geological settings...in corundums are in equilibrium and/or postdate corundum crystallization and comprise: spinel and pargasite...peak. The Paranesti, Xanthi and central Naxos corundum deposits can be classified as metamorphic sensu...be considered as potential gemstones. Keywords: corundum megacrysts; ruby; sapphire; plumasite; metamorphic-metasomatic |  | | Book | | .......................... 73 9.10 Rubine aus Mangari, Kenia ................................... 74 9...Tansania Longido, Tansania Morogoro, Tansania Mangari, Kenia Fiskenaesset, Grönland 0,19-0,20 0-0,02...Qualität im Handel. Obwohl das Rubinvorkommen im Mangari-Distrikt, Kenia, größtenteils Cabochonware geliefert...Tansania Longido, Tansania Morogoro, Tansania Mangari, Kenia Fiskenaesset, Grönland Prilep, Jugoslawien...erfolgt. Bei Rubinen einiger Fund punkte (z.B. Mangari, Kenia, und Umba, Tansania) gehen von den zuvor |  | 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) | | 3 ARTICLE Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological...Abstract The oxygen isotopic composition of gem corundum was measured from 22 deposits and occurrenEditorial...geological identification and characterization. Primary corundum deposits in Madagascar are hosted in magmatic...deposits, provoked in situ transformation of the corundum host rocks with the formation of metasomatites...marble from Andranondambo). The δ18O values for gem corundum from secondary deposits have a wide spread between |  | Sutherland, F. L., Coenraads, R. R., Schwarz, D., Raynor, L. R., Barron, B. J., Webb, G. B. (2003) Al-rich diopside in alluvial ruby and corundum-bearing xenoliths, Australian and SE Asian basalt fields. Mineralogical Magazine, 67 (4) 717-732 doi:10.1180/0026461036740129 | Journal (article/letter/editorial) | | 717–732 Al-rich diopside in alluvial ruby and corundum-bearing xenoliths, Australian and SE Asian basalt...proposed for Thailand rubies and a xenolith of corundum-bearing garnet granulite from Ruby Hill, Bingara...similarities with eastern Thailand rubies. K EY WORDS : corundum, ruby, sapphire, diopside, alluvial, xenocryst...dark coloured ruby forms about half the alluvial corundum suite (Webb, 1997) and has an inferred resource...describe pink to red and blue to green alluvial corundum suites from the Cudgegong-Macquarie River system |  | 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) | | Pre-proof Formation, origin and geographic typing of corundum (ruby and pink sapphire) from the Fiskenæsset...al., Formation, origin and geographic typing of corundum (ruby and pink sapphire) from the Fiskenæsset...GEOGRAPHIC FROM THE FISKENÆSSET COMPLEX, TYPING OF CORUNDUM (RUBY AND PINK SAPPHIRE) GREENLAND Nynke Keulen1...Here, we refer to all red and pink corundum as ruby and to all corundum of other colours as sapphire(s)...ruby-bearing schist consists of biotite surrounding corundum and plagioclase, with minor amount of al orthopyroxene |  | | Journal (article/letter/editorial) | | Guo ? Suzanne Y. O’Reilly William L. Griffin Corundum from basaltic terrains: a mineral inclusion approach...Abstract This paper investigates the origin of corundum megacrysts that occur in many basaltic terrains...for over 80 primary mineral inclusions within corundum megacrysts are used to gain a new insight into...of the corundum megacrysts. A wide spectrum of minerals is present as inclusions in the corundum; the most...minerals from corundum occurring in widely separated areas suggests that the corundum megacrysts in basalts |  | | Journal (issue) | | as Ramona Ramona County, County, California, California, Macon Macon County, County, Virginia, Virginia...Madagascar, Madagascar, Sri SriLanka Lanka and and Kenya, Kenya, have have been been very very erratic, erratic...803 Rutherford Mine, Virginia1 1.802(3) Taita Hills, Kenya 2 1.795-1.809 Minas Gerais, Brazil3 1.803-1...Spessartine aus den Taita Hills, Kenia. Der Aufschlufi, Spessartine aus den Taita Hills, Kenia. Der Aufschluß...previously been been noted noted within within Kenya, Kenya, Tanzania, Tanzania, Sri Sri Lanka, Lanka, India |  | | Journal (issue) | | thousands, of dollars. Ruby is a gem variety of corundum (Al2O3) that is colored red by trivalent chromium...[V] and iron [Fe]) substitute for Al3+ in the corundum crystal structure, or they may be present as various...Morogoro, Tanzania—Ti, Si, Cr, Fe, V; Tsavo Park, Kenya—Cr, Fe, Si, Ti, V; Rajasthan, India—Fe, Si, Ti,...influences the assemblage of trace elements present. Corundum (Al2O3) crystallizes only in silica-deficient...India—southern (Viswanatha, 1982; Menon et al., 1994) Kenya—Mangari (Pohl et al., 1977; Pohl and Horkel, 1980; Bridges |  | | Journal (article/letter/editorial) | | range of environments and conditions involved in corundum (Al2O3) formation. We compiled a global data base...Introduction Sapphire and ruby are gem varieties of corundum (αAl2O3): rubies are red, and sapphires are any...Rakotosamizanany et al. 2014). Geochemical investigations of corundum are somewhat restricted in scope because only...zone; continental collision crystal structure of corundum (e.g. Wong et al., 2017), but oxygen isotope ratios...variation in corundum δ18O is potentially related to the tectonic environment during corundum formation |  | | Journal (issue) | | of untreated rubies, and characterizes the gem corundum produced there, which arrived on the market in...deposits at Winza in central Tanzania. The gem corundum is related to “dikes” of amphibolitic rocks that...Usagaran Belt. Based on crystal morphology, Winza corundum is subdivided into two types: prismatic-tabular-rhombohedral...crystals), fissures, and growth features. Unique to corundum from this locality are bluish violet color zones...ruby-producing localities such as Lossogonoi, the corundum is found in “anyolite,” a rock composed of green |  | 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) | | Published: 30 June 2020 Abstract: Corundum is not uncommon on Earth but the gem varieties...of ruby and sapphire are relatively rare. Gem corundum deposits are classified as primary and secondary...secondary deposits. Primary deposits contain corundum either in the rocks where it crystallized or as xenocrysts...the Earth’s surface. Classification systems for corundum deposits are based on different mineralogical...is the red gem variety of the mineral corundum. The name corundum was introduced in the early 19th century |  | | Journal (issue) | | (Myanmar, Thailand, and Vietnam), Africa (Tanzania, Kenya, Zimbabwe, Nigeria, and Namibia, as well as Madagascar)...cat’s-eye chrysoberyl as well as alexandrite. CORUNDUM Ruby. The 1990s witnessed continued supplies of... African sources include several localities in Kenya, Tanzania, and Madagascar. In particular, the John...John Saul mine in GEMS & GEMOLOGY Winter 2000 Kenya began producing large quantities of (mostly cabochon-grade)...Localities of the 1990s GEMS & GEMOLOGY Winter 2000 Corundum—Ruby. As was the case with emeralds, ruby prices |  | Giuliani, Gaston, Fallick, Anthony E., Boyce, Adrian J., Pardieu, Vincent, Pham, Van Long (2017) Pink and Red Spinels In Marble: Trace Elements, Oxygen Isotopes, and Sources. The Canadian Mineralogist, 55 (4) 743-761 doi:10.3749/canmin.1700009 | Journal (article/letter/editorial) | | Nepal, Kiswila and Ipanko in Tanzania, Pamreso in Kenya, Mogok in Myanmar, and An Phu in Vietnam. The variation...Occurrences are known in Pakistan, Afghanistan, Nepal, Kenya, and Mozambique (Vertriest & Pardieu 2016). Secondary...conditions. The main equilibrium reaction between corundum and spinel during prograde metamorphism is the...Spl þ Cal þ CO2. This reaction explains why gem corundum and spinel are generally not associated in the...Neoproterozoic metamorphic Mozambique Belt. In Kenya, the Pamreso spinel occurrence, in the Voi region |  | | Journal (article/letter/editorial) | | Massif Central: implications for the origin of gem corundum in basaltic fields Gaston Giuliani & Anthony Fallick...2004) and are generally found in corundum-bearing xenoliths, or as corundum xenocrysts that have been transported...“metamorphic” ones (Sutherland and Schwarz 2001). The corundum crystals termed “magmatic” are xenocrysts of blue-green-yellow... ferrocolumbite, zircon, and iron oxides. The corundum crystals termed “metamorphic” are pastel (blue...the isotopic composition of framework oxygen in corundum was used in order to decipher their origin (Giuliani |
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