 | | Book | | noted gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical...pink diamonds. Emerald, alexandrite, garnet, and tourmaline are all significantly present. New discoveries...interest. Rare and unusual garnet and chrome tourmaline are widely identified with the region. ( continuedon...69-carat chrome tourmaline. Courtesy of the 'Irelawney Collection of the Los Angeles County Museum of Natural...Tanzania 32 Sapphire from Kenya 42 Ruby from Mangari, Tsavo West National Park, Kenya 44 Chapter 4. Emerald |  | | 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...and sapphire.. The ruby deposits in the Mangari area of SE Kenya, are among the most productive and best...dominated by sillimanite-graphitic gneisses, the Mangari deposits are associated with rootless ultrabasic...and pressures which did not exceed 7 kbar. At Mangari, the ruby-bearing rocks, as their associated ultrabasites...reserved. Keywords: ruby deposits; Mozambique Belt; Kenya; ultrabasites; granulite facies 1. Introduction |  | 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) | | Ma for the Aqua Ruby mine, both in the Mangari area of Kenya, and an age of 499 ± 12 Ma for ruby from...Corundum . U–Pb LA-ICP-MS dating . Mozambique belt . Kenya . Tanzania Editorial handling: B. Lehmann * Elena...ruby mine and the Aqua mine, both in the Mangari area of Kenya, and Morogoro in Tanzania. Geological setting...(Giuliani et al. 2007) (Fig. 1). Mangari deposits of Kenya In the Mangari area, primary gem corundum occurs...and light grey soil Augen gneiss Hyderabad Mangari, Kenya, E Nairobi corundum Biotite-garnet quartz |  | | Journal (issue) | | Alternatively, the stone could have been a large tourmaline crystal, possibly red in colour and from Burma...tetragonal crystals and rounded pebbles. Red Tourmaline: pania turemali, penni tourmalin; rod turmalin...other colours of zircon, called indiscriminately 'tourmaline', even today. Blue Saphire: nilem, nile; blâ...or yellowish-brown garnet". Grossular. Yellow Tourmaline or Maturese Diamond: kaneke turemali (both Malab...black to brown or reddish-brown strongly dichroic tourmaline crystals commonly found in Sri Lankan gem gravels |  | | 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) |  | 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) | | evolution of corundum crystals from deposits in Africa (Kenya, Tanzania, Madagascar) and Southeast Asia (Vietnam)...color in corundum from two deposits in the Mangari area in Kenya have Cr concentrations of ~200–700 mg/g...mg/g in samples from Luc Yen (Vietnam) and Mangari (Kenya), formed under lower P-T. Concentrations of...evolution, genesis, geochemistry, crystal morphology, Kenya, Tanzania, Madagascar, Vietnam Introduction “…for...from five important deposits in Africa (Mangari area in Kenya, Morogoro in Tanzania, and Andranondambo |  | | Journal (article/letter/editorial) | | 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...gem-corundum deposits compared with East Africa (Kenya,Tanzania),India and Sri Lanka, its pre-breakup surrounding...representative East African ruby deposits of Mangari in SE Kenya, and of Longido and Lossogonoi in northern...Lossogonoi respectively, in Tanzania; 4) Mangari in SE Kenya, a s well as the green grossular garnet deposits |  | | Journal (issue) | | inclusions orientated perpendicular to the c-axis. A tourmaline-quartz combination from Brazil has an iridescent...albite-oligoclase orthoclase perthite. Four-rayed star tourmaline (bicolour elbaite) has one direction caused by...new unusual cat's-eyes and star stones Quartz-tourmaline cat's-eye from Brazil A strange stone weighing...from a pegmatite in Minas Gerais. The base is tourmaline with a transparent light green core with a dark...structure. The next phase of growth on the green tourmaline consisted of thin tourmalines and white hexagonal |  | | Journal (article/letter/editorial) | | taaffeite, topaz, tremolite, minerals of the tourmaline supergroup, vesuvianite, zircon, zoisite. Non-gemmologists...pallasite meteorites, gem benitoite from San Benito County California, and Colombian emeralds (for whose genesis...that has been successfully used in prospecting in Kenya, Brazil, and no doubt elsewhere. Association with...flakes of muscovite, across a stream from a gem tourmaline mine, Minas Gerais, Brazil. Photo: J. Saul. ...from the Scorpion Mine (Mgama Ridge, southeast Kenya) could be mined with a teaspoon (Bridges 2007; Campbell |  | 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) | | phlogopite, anorthite, corundum, chlorite, zoisite, tourmaline and beryl. Anorthite crystals are composed almost...phlogopite, rutile, titanite, anorthite, garnet and Ni-tourmaline [22,23,27,42]. Spinel occurs as a rim around...(plumasite) and associated with phlogopite and tourmaline anorthite-rich desilicated pegmatite (plumasite)...(plumasite) and associated with phlogopite and tourmaline (schorlite)from fromthe thefirst firstKinidaros Kinidaroslocality...the plagioclase matrix, and/or associated with tourmaline, and phlogopite (Figure 3g,h). Purple to pink |  | | 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 AufschluĂź...previously been been noted noted within within Kenya, Kenya, Tanzania, Tanzania, Sri Sri Lanka, Lanka, India |  | Giuliani, Gaston, Fallick, Anthony, Rakotondrazafy, Michel, Ohnenstetter, Daniel, Andriamamonjy, Alfred, Ralantoarison, ThĂ©ogène, 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) | | pegmatites with deep-blue colored beryl and polychrome tourmaline, rhodizite, morganite, orthoclase (Lacroix 1922a)...494±5 Maa Phlogopite– cordierite– sapphire– tourmaline–spinel– saphirine Granulite facies Biotite–sapphire–...alexandrite, topaz, garnet, spinel, andalusite, and tourmaline. (3) Other placer deposits of unknown origin:...of primary and secondary deposits of Madagascar, Kenya, Tanzania, Sri Lanka, and India (data from Giuliani...Saul type Machanga John Saul mines Garba Tula Kenya West Pokot Mica Kitui GL mine Songea Tunduru |  | | Journal (issue) | | covellite dendrites • Induced copper contamination of tourmaline pg. 353 369 Gem News International Andesine...Tanzania and Kenya. Most of the known gem corundum occurrences in Tanzania and southeastern Kenya—including...Kenya—including Longido, Umba, the Mangari area, Morogoro, and Mahenge—belong to the granulite-facies Eastern Granulites...various types of primary and secondary deposits in Kenya and Tanzania. The data are reported in the conventional...distinguished by relatively high Cr contents. Mangari rubies typically have low Fe (mostly, <0.05 wt |  | | Journal (issue) | | 4.82 ct purple sapphire, (10) 5.32 ct ParaĂba tourmaline, (11) 2.16 ct demantoid, (12) 1.05 ct emerald...(Myanmar, Thailand, and Vietnam), Africa (Tanzania, Kenya, Zimbabwe, Nigeria, and Namibia, as well as Madagascar)...peridot, quartz, spinel, tanzanite, topaz, and tourmaline). Locality information is both summarized in... 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) |  | | Journal (issue) | | Morogoro, Tanzania—Ti, Si, Cr, Fe, V; Tsavo Park, Kenya—Cr, Fe, Si, Ti, V; Rajasthan, India—Fe, Si, Ti,...phlogopite, rutile, Cr-muscovite, chlorite, tremolite, tourmaline, apatite, sphene, anorthite, margarite, pyrrhotite...1990b) Pakistan—Kashmir (“Kashmir Yields Ruby, Tourmaline,” 1992; Kane, 1997) Russia—Ural Mountains (Kissin...Plagioclase, vermiculite, phlogopite, muscovite, tourmaline (highly variable) Rutile, boehmite; sometimes...India—southern (Viswanatha, 1982; Menon et al., 1994) Kenya—Mangari (Pohl et al., 1977; Pohl and Horkel, 1980; Bridges |  | 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) | | Vohitany; Ejeda). Ethiopia: (5) Kibre mengist, Dilla. Kenya: (6) West Pokot; (7) Baringo; (8) Kitui; Gogogogo;...Vohitany; Ejeda). Ethiopia: (5) Kibre mengist, Dilla. Kenya: (6) West Pokot; (7) Baringo; (8) (9) Kitui; Mangare...and theand Rockland (former John Saul) mine in Kenya stopped producing. Africa (Figure 4) gem rubies...John Saul) mine in Kenya stop ucing. In Africa (Figure 4) gem rubies are mined in Kenya (Mangare and Baringo)...Baringo and Antanifotsy (Soamiakatra) deposits in Kenya deposits in Kenyarespectively. and Madagascar, respectively |  | | Journal (article/letter/editorial) | | (Thailand, Vietnam and Cambodia) and northern Africa (Kenya and Nigeria). Notwithstanding these observations...Arizona San Carlos 110830’W 33825’N Mangari (Uncertain) Kenya demonstrates that the alluvial corundum...area in Thailand (Table 1). Other samples from Mangari, Kenya and San Carlos, USA also were examined. Most...calcite, dolomite, phlogopite, muscovite, biotite, tourmaline, graphite, columbite, pyrochlore and almandine...phonolites and trachytes from the summit region of Mt Kenya. Contrib Mineral Petrol 89: 394–409 Pupin JP (1980) |  | 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) | | (OH)-bearing silicates; presence of both kornerupine and tourmaline in some of the reaction zones indicate boron...zircon have been described for pr rubies from Mangari, Kenya (Smith 2014). Zircon is a less common inclusion...negative crystals are commonly observed in e.g., Mangari, Kenya (Smith, 2014), in Mogok, in various magmatic... Zonal clouds are reported for rubies from Mangari, Kenya, while milky zones more commonly occur in,...(Myanmar), Hunza (Pakistan) rn and Mangari (Kenya). In Mangari, rubies are found associated with small |  | | Journal (article/letter/editorial) | | comprises hercynite- and corundum-bearing zones. Tourmaline-rich zone only occurs when the pegmatite veins...garnet-biotite/phlogopite geothermometer, and the higher tourmaline XMg, strongly indicate amphibolite facies 1 ...the Hafafit complex. Restricted occurrence of tourmaline-rich zone at the ultramafic-granitic gneiss contact...biotite-rich granitic gneiss. Keywords: Corundum, tourmaline, hercynite, desilicated pegmatite, peridotite...(hercynite), allanite, almandine-rich garnet, tourmaline, margarite, vermiculite, anthophyllite, enstatite |  | 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...Neoproterozoic metamorphic Mozambique Belt. In Kenya, the Pamreso spinel occurrence, in the Voi region...from 6000 to 11,000 ppm while that of Pamreso in Kenya is between 4400 and 6300 ppm. The Mogok and Namya...WORLDWIDE DEPOSITS Country Deposit Sample Color Kenya Pamreso Myanmar Mansin Mogok Mogok Namya Nepal |  | | Journal (issue) | | Practical Gemmology The Kerez effect in green tourmaline 654 Gem Notes Apatite from Mozambique| Chondrodite...from Kenya|Shattuckite and bisbeeite from the DRC| Purple tourmaline from Mozambique|Tourmaline slices... Practical Gemmology The Kerez Effect in Green Tourmaline Andrew Fellows The Kerez effect refers to an...behaviour that is very rarely shown by green tourmaline. Since it is so uncommon, it often goes unreported...a single set of readings that were normal for tourmaline. Therefore, the correct RI range for the 1.39 |  | | Journal (issue) | | Sapphire Robert E. Kane 40 Interesting Red Tourmaline from Zambia Iohn I. Koivula and C. W. Fryer ...recent years. Two articles in this issue deal with tourmaline: one with the (lrecl that hns prod~rcedmore tourlnaline...Brazil; the other with (I new locality for red tourmaline-Zcrmbia. The pendanr shown here well illustrates...most important producers of fine aquamarine, tourmaline, and topaz in the world today. With the award...Minas Gerais I n the history of gemstones, tourmaline is a latter-day Cinderella. Whereas aquamarine |  | | Journal (issue) | | (4) 8.14-ct grossular garnet, Kenya; (5) 16.28-ct rubellit8 tourmaline, Queen Mine, Pala, California;...California; (6) 15.18-ct tourmaline, Paraiba, Brazil; (7) 10.42-ct tanzanite, Tanzania; (8) 6.09-ct spessartite...spessartite, Ramona, San Diego County, California; ( 9 ) 10.45-ct tsavorite, Kenya; (10) 4.82-ct emerald, Colombia;...diamond; (16) 6.38-ct ruby, Burma; (17) 3.08ct tourmaline, Paraiba, Brazil; (18) 1.85-ct fancy purple-pink...courtesy of the Natural History Museum of Los Angeles County; 6 is courtesy o f DuQuet lewelers, Inc.; 7 is |  | | Journal (article/letter/editorial) | | Proterozoic rocks in the Caledonides, Nordland County, Norway (Grauch et al. 1994; Burt 1994). The mineral...05 16.55 wt.% (minimum and maximum from Mangari area, Kenya and Vizianagaram, India, by Mercier et al...peralkaline syenite autolith, from Kilombe volcano, Kenya, with 5.98 7.93 wt.% MnO, which corresponds to 1...in aenigmatite from nepheline syenite on Mount Kenya. Aenigmatite found in an albite clast in the Kaidun...contrast to the magnesian aenigmatite from Mount Kenya, in which divalent cations total 8.5 9.0 per 28 |  | | Journal (issue) | | moissanite • Fracture fillers in ruby • ParaĂba tourmaline 260 Gem News • APEC 2000 report • De Beers’s...sugilite with green spots • ParaĂba tourmaline update • “Winebottle” tourmaline • Magnetic hematite imitation...from a light blue similar to that of ParaĂba tourmaline or apatite, to a dark blue similar to that described...regarding this glassy material. MLJ and SFM TOURMALINE Rough from ParaĂba some of the materials Themelis...stone, which he had purchased in Brazil, was tourmaline from ParaĂba. Although he was offered smaller |
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