 | | Journal (article/letter/editorial) | | Variably colored grossular specimens from the Jeffrey mine in Canada have previously been featured as a Connoisseurâs...Tanzanian tsavorite has types 2, 3, and 4 represented; Kenya tsavorite is only types 2 and 4. The original discovery...tsavorite was named after Tsavo National Park in Kenya, located close to the border with Tanzania (figs...tsavorite in Tanzania and subsequent discovery in Kenya in 1970 by the geologist and gem prospector Campbell...Bridges and Walker (2014). Prior to its discovery in Kenya, Bridges had found âtsavoriteâ Figure 2. A rough |  | | Book | | noted gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical...200 known here-holds the productive Mwadui diamond mine, known for Yeryfine, rare, pink diamonds. Emerald...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 |  | 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) | | formation of gem tsavorite garnet in the Voi area (southwestern Kenya) J.-B. Jacob, J.-E. Martelat, P. Goncalves...formation of gem tsavorite garnet in the Voi area (southwestern Kenya). Lithos (2018), doi:10.1016/ j.lithos...formation of gem tsavorite garnet in the Voi area (southwestern Kenya) J-B. Jacoba,*, J-E. Martelata,**, P...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 ïȘïȘ Principal corresponding author ED *Corresponding |  | | Journal (issue) | | on the growth of vanadium grossular garnets in Kenya R.M. Key, FGA*, andP.G.Hill** *British Geological...growth of green vanadium grossular garnet in SE Kenya ascertainedthe chemistry of the host graphitic gneisses...gneisses and on metamorphic conditions in SE Kenya are preby Pohl and Neidermayr (1978) are confirmed...complex Upper Proterozoic to around garnet pods in SE Kenya are not retrogressive Lower Phanerozoic province...their work in SE Kenya, Pohl and Neider- also found on either side of the Tanzania/Kenya mayr (1978) concluded |  | | Book | | MINERALS& GEMSTONES of East Africa Burundi, Kenya, Rwanda, Tanzania and Uganda Bruce Cairncross Published...rutile crystals partially included in transparent quartz crystals, 3 cm - Philip Hitge specimen, Bruce Cairncross...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 |  | | Journal (issue) | | (lithium tourmaline) was made at the Dunton gem mine, Newry, Maine, U.S.A. The narrative of discovery...England "watermelon" tourmaline had come from this mine in years gone by, although most of it was not facet-grade...after two years of semi-continuous operation of the mine. T h e elbaite is being mined from collapsed gem...Instrumentale, 6, 127. 385 RED DRAVITE FROM KENYA By PETE J. DUNN, M.A., F.G.A., JOEL E. AREM, Ph...the authors (J.S.) at Osarara, Narok District, Kenya. The deposit is located at 1° 34' S, 35° 46' E, |  | | Report (issue) | | you is an Arkansas quartz. It came in March 2017 from a pocket in the McEarl Ridge mine near Jessieville...Jessieville, also called the James Zigras mine, because that worthy collector out of Paramus, New Jersey has been...been working during the past few years to extract quartz specimens, many of which have turned out to be...but this piece, consisting of a single 14.7-cm quartz prism with some smaller, iron-stained crystals...the best from that case. Quartz, 14.7 cm, from the Zigras (McEarl Ridge) mine, Jessieville, Arkansas. |  | Dachs, E., Geiger, C. A., Benisek, A., Grevel, K.-D. (2012) Grossular: A crystal-chemical, calorimetric, and thermodynamic study. American Mineralogist, 97 (8) 1299-1313 doi:10.2138/am.2012.4047 | Journal (article/letter/editorial) | | the reaction 3anorthite = grossular + 2kyanite + quartz were analyzed thermodynamically. The calculations...two different garnets from the wellâknown Jeffrey mine locality of Asbestos, Quebec, Canada (Allen and...green in color and comes from a locality at Lualenyi, Kenya (Gr-L/K), that is well known for its tsavorite...composition (see below) it may also originate from Lualenyi. All the natural garnets occur in singleâcrystal...(Grâ)82â112 Jeffrey Mine, Asbestos, Quebec Natural Gr (Hessonite); CMNMC (Grâ)44091 Jeffrey Mine, Asbestos, |  | Arneth, J.D., Schidlowski, M., Sarbas, B., Goerg, U., Amstutz, G.C. (1985) Graphite content and isotopic fractionation between calcite-graphite pairs in metasediments from the Mgama Hills, Southern Kenya. Geochimica et Cosmochimica Acta, 49 (7) 1553-1560 doi:10.1016/0016-7037(85)90260-1 | Journal (article/letter/editorial) | | in m~~sed~rn~nts frarn the Mgama Hills, Southern Kenya J. D. ARNETW, M. SCHIDLQWSKI Mu-P~anck-~nstitot...rade me&sediments from the Mgama Hills region, Kenya, contain conspicuous quantities of graphite, most...impure varieties containing conspicuous amounts of quartz, plagioclase, mica. kyaniie, scapoiite and graphite...THE MGAMA Hm..s rne~rno~~~c complex of Southern Kenya is part of the Proterozaic Mozambique Belt of Eastern...metamorphic sequence and tremotite + 3 calcite + 2 quartz to obtain inde~nde~t constraints on the tem~mtures |  | | Journal (issue) | | its membership, all sectors of our industry from mine to market in 45 diïŹerent countries and is engaged...discovered a second deposit across the border in Kenya, near Tsavo National Park. The Kenyan governmentâs...who in 1973 discovered yet another deposit at Lualenyi, just a few kilometers north of Bridgesâ claim...1992). A gem rush soon ensued and the nearby town of Voi quickly transformed into an active gem-trading center...Wangui Gladwell, the daughter of the Baraka mine owner in Kenya, used in the trade and in this article refer |  | | Journal (issue) | | Pakistan and Vietnam|Bicoloured grossular from Kenya|Jade-like materials sold in Myanmar|Blue kyanite...Tanzania|Rainbow moonstone from Malawi|News from the Oceanview mine, Pala, California|Scheelite from Inner Mongolia|Aging...Discoverer of TsavoriteâCampbell Bridgesâand His Scorpion Mine By Bruce Bridges and Jim Walker Gemmological Briefs...in emeralds fracture-filled with resin and oil, quartz coated with diamond chips, âBumble- 185 Whatâs...flexibility, I 188 Figure 1: This polished crystal of quartz (reportedly from Brazil) contains a series of inclusions |  | Giuliani, Gaston, Dubessy, Jean, Ohnenstetter, Daniel, Banks, David, Branquet, Yannick, Feneyrol, Julien, Fallick, Anthony E., Martelat, Jean-Emmanuel (2018) The role of evaporites in the formation of gems during metamorphism of carbonate platforms: a review. Mineralium Deposita, 53 (1) 1-20 doi:10.1007/s00126-017-0738-4 | Journal (article/letter/editorial) | | vanadium-rich zoisite, called tanzanite, from Tanzania, Kenya and Madagascar, and lapis-lazuli in marble and/or...emerald and quartz, Muzo mines, western emerald belt, Colombia. c Emerald crystals on quartz and adularia...flakes of phlogopite in a marble matrix, Minh Tien mine, Luc Yen mining district, Vietnam, 2 Ă 1 cm. e Nodule...tsavorite from the Tsavolite mine, Mangare mining district, Voi region, Kenya, diametre of the nodule (on...Vapnik and Moroz 2001). Emerald is confined to quartz-ankeritedolomite-pyrite veinlets and veins linked |  | | Journal (article/letter/editorial) | | tsavorite. Following the formation of tsavorite in quartz veins in the anticlinal folds, crystalized tanzanite...(brown and yellow), graphite, diopside, pyrite, quartz, grossular (tsavorite), dolomite, and calcite [11]... Composition of green garnet from Tanzania and Kenya. Gems Gemol. 1974, 14, 296â297. Wilson, W.E.; Sau...diopside, and associated minerals from the Karo mine, Block D, Merelani Hills, Arusha region, Tanzania...Green vanadium grossular garnet from Lualenyi, near Voi, Kenya. Lapidary J. 1975, 29, 402â426. Giarola |  | Feneyrol, J., Ohnenstetter, D., Giuliani, G., Fallick, A. E., Rollion-Bard, C., Robert, J.-L., Malisa, E. P. (2012) EVIDENCE OF EVAPORITES IN THE GENESIS OF THE VANADIAN GROSSULAR 'TSAVORITE' DEPOSIT IN NAMALULU, TANZANIA. The Canadian Mineralogist, 50 (3) 745-769 doi:10.3749/canmin.50.3.745 | Journal (article/letter/editorial) | | Mozambique Belt. The graphitic gneiss is composed of quartz, V-bearing kyanite (up to 0.4 wt.% V2O3), V-bearing...mobilizing the elements for tsavorite crystallization in quartz-calcite veins. The dolomitic marble unit hosts...Mozambique Belt (Walton & Marshall 2007) of southeastern Kenya (Pohl & Niedermayr 1978, Suwa et al. 1996), northeastern...2010a). The presence of scapolite in southeastern Kenya (Suwa et al. 1996) and gypsum and anhydrite in northeastern... biotite-graphite gneiss, calc-silicate rocks, quartz-orthoclase-oligoclase-andesine gneiss, dolomitic |  | | Journal (issue) | | bicolored tounnaline (12.90 ct), all from the Himalaya mine (California). Thestones were faceted by PalaInteri~ntional...the Virgem da Lapa group, thc Salinas mine, and the Ouro Fino mine are especially noteworthy and are described...lzunzites) were also found in this district, in the Neves mine (Lindner, 1966, 1967; Lindner and Rolff, 1968; Rolff...green and blue-green tourmaline from the Pirineus mine is among the best ever found in Brazil, but only...(Levon Nercessian, pers. comm., 1985). The Piaui mine also produced fine green and blue-green rough, approximately |  | | Journal (issue) | | 1st April, 1981] ENSTATITE FROM MAIRIMBA HILL, KENYA By Dr K. SCHMETZER and Dr H. KRUPP Heidelberg, W...green colour from the region of the Mairimba Hill, Kenya, is described. The crystals have refractive indices...of 1.45% FeO and 0.22% Cr2O3. During a visit to Kenya in the beginning of 1981, one of the authors (H...localities in Tanzania. No data for samples from Kenya are published or available. Enstatite is the magnesium...the Mairimba Hill region, south of the Taita Hills, southern Kenya. Other gem minerals from this locality |  | Feneyrol, Julien, Giuliani, Gaston, Ohnenstetter, Daniel, Rondeau, Benjamin, Fritsch, Emmanuel, Fallick, Anthony E., Ichang'i, Daniel, Omito, Edward, Rakotondrazafy, Michel, Ranatsenho, Madison, Lallier, Florent (2014) New typology and origin of tsavorite based on trace-element chemistry. European Journal of Mineralogy, 26 (2) 293-308 doi:10.1127/0935-1221/2014/0026-2367 | Journal (article/letter/editorial) | | University of Nairobi Nairobi, Kenya 7 Mines and Geology Department, Wundanyi, Kenya 8 FaculteÌ des Sciences...geographic provenance of economic tsavorite from Kenya, Tanzania and Madagascar. Key-words: tsavorite,...(Bridges, 1974). The economic deposits are located in Kenya, Tanzania and Madagascar but other small occurrences...Tsavorite is mined presently only in southeastern Kenya (Pohl & Niedermayr, 1978; Suwa et al., 1996; Feneyrol...microprobe analysis. His analyses of green garnets from Kenya and Tanzania showed that vanadium was the most important |  | | Journal (issue) | | consist of flow texture, microcrystalline granular quartz/chalcedony, and inclusions of zeolites. Several...discoloration and a thin zone of microcrystalline quartz (?) at the contact with the opal. (Opal is broken...araldite resin (1.62)) and a hardness much lower than quartz. Its XRD data are identical with clinoptilolite...thin band of what appears to be microcrystalline quartz. A similar zone surrounds the tuff inclusions at...matter (opal-A) to opal-CT/opal-C and finally to quartz has been known from early investigations of diagenetic |  | | Journal (issue) | | Olmec carvings in jacleite, with jadeite and rose quartz beads, are typical of jewelry found in tourist...locally and in the trade as the original tanzanite mine is actually a mining belt about 4 x 1 lzm which...mineralogy at the Natural History Museum of Los Angeles County, Los Angeles, California; and Dr. Krupp is a physicist...West Germany, and has made more than 60 trips to Kenya and Tanzania to purchase gem rough. Acknowledgments:...Campbell R. Bridges, of Bridges Exploration (Nairobi, Kenya), for helpful comments on the manuscript and for |  | | Journal (issue) | | marketed, and merchandized. In diamonds especially, the mine-to-market process has been severely tested. Vertical...(Myanmar, Thailand, and Vietnam), Africa (Tanzania, Kenya, Zimbabwe, Nigeria, and Namibia, as well as Madagascar)...jade [both jadeite and nephrite], opal, peridot, quartz, spinel, tanzanite, topaz, and tourmaline). Locality...reference to the country rather than to the specific mine or region. For more on the specific localities,...produce attractive emeralds. Zimbabweâs Sandawana mine is noted for small stones (0.05 to 1 ct) of high |  | | Journal (issue) | | and the ethylene dibromide, I took a large clear quartz polished piece used by B.W. Anderson as a check...1980, XVII, 2 doubly terminated Herkimer ordinary quartz crystal finely suspended (very enjoyable). Having...clustered around, slightly above and slightly below the quartz in suspension, offering a density range of 2.650-2...fact they behaved as good party members of the quartz group (density branch) exhibiting solidarity with...Birefringence small 0.004. Specific Gravity 2.65 (quartz matching liquid). Absorption Spectrum a strong |  | | Journal (issue) | | is initially used to divide the incoming "run-of-mine" shipments of diamonds into two groups called smalls...fall through an optical "box". This box contains quartz halogen lamps and photomultipliers, which measure...the Novello Prospect a n d the abandoned Twin Star Mine, both of which are located about 17 km N W . of...located some 6 km north of the famous Bikita lithium mine about 80 km east of Fort Victoria. Details of the...Shamvaian age (2,650 m. years). T h e Twin Star mine is only 6 or 7 km distant from the Novello Prospect |  | | Journal (issue) | | quality (tsavorite) is known from East Africa (Kenya, Tanzania; Bridges, 1974) and, to a lesser extent...assemblage including plagioclase (anorthite), diopside, quartz, graphite and sphene, minerals which may be partially...garnet Location 1 Madagascar (Gogogogo) Kenya (Lualeni)1 Kenya (Lualeni) Rl SG 1.742 3.62 1.743 3.61...occurred in the gemmological literature spelled Lualenyi J. Gemm., 1997, 25, 6, 391-393 Some physical...characteristics similar to those measured for specimens from Kenya, Tanzania (GĂŒbelin and Weibel, 1975; Manson and |  | | Book | | natural, cultured and imitation Alexander E. Fam Quartz Michael O'Donoghue In preparation Jet and amber...ancient mine sites from Greek and Roman authors who were not in the gem trade. Fictional mine sources...could also hamper modern efforts in locating ancient mine sources. However, Theophrastus is quite explicit...One thing seems certain, however: the Carthaginian mine source must have been rather extensive, lasting...species studied. The garnets which have exceeded quartz in hardness (7) have been widely used as abrasives |  | | Journal (issue) | | world-famous Pala pegmatite district in San Diego County will take place August 25, 2006. No more than 50...inclusions in Colombian emeralds, and pyrite in quartz or emerald (figure 4, middle). 1967 1968 1967...on green grossular garnet (tsavorite) deposit in Kenya 1969 Publishes Edelsteine, translated in 1975 as...host). Middle: This pyrite crystal in Brazilian quartz (left, 25Ă) and the threephase inclusions in Colombian...apatite and calcite in hessonite. Also consider quartz, which Dr. GĂŒbelin once said he regarded as the |
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