 | | Journal (article/letter/editorial) | | 1990 Rare-metal pegmatites of Wamba, central Nigeria their formation in relationship to late Pan-African...mineralization of the Wamba field (central Nigeria) occurs in muscovite-quartz-microcline pegmatites, which are...central Nigeria (Jacobson & Webb 1946; Wt:ight 1970). The primary mineralization is hosted in quartz-feldspar-muscovite...Granites" of Nigeria. The two periods and styles of rare-metal mineralization in Nigeria were already...derivation of the rare-metal pegmatites of southwestern Nigeria from reactivation of tectonic lineaments combined |  | | Journal (issue) | | range of emeralds and green beryls from Central Nigeria. Detailed work on inclusions, compositions of hosts...Natrolite Petalite Leucite Oligoclase Quartz Synthetic quartz Iolite Scapolite Labradorite Beryl 2.91...deposits are exploited, e.g. in Australia, Thailand, Nigeria and China (Coenraads, 1992a; Guo et al., 1992)...transparent), magnetite, hematite, rutile, pyrite and quartz (originating from the Precambrian rocks). regional...on sapphire from other basaltic origins (e.g. Nigeria and Australia). She described as significant morphological |  | | Journal (issue) | | from Transvaal); Zambia (30 from Kafubu); Nigeria (30 from Gwantu); and China (10 from Malipo). The 66 faceted...(Kafubu, Zambia). The exact posi- Colombia (Ch) 68 Nigeria (Gw) China (Ma) Brazil (ST) Brazil (So) Brazil...GEMOLOGY WINTER 2014 289 68 Colombia (Ch) Nigeria (Gw) China (Ma) 67 Brazil (ST) Brazil (So) Brazil...306±0.284 0.405±0.053 Nigeria/Gwantu 1 66.254±0.168 0.208±0.021 Nigeria/Gwantu 2 66.188±0.056 0.142±0...142±0.018 Nigeria/Gwantu 3 64.986±0.409 0.230±0.041 Nigeria/Gwantu 4 65.755±0.220 0.208±0.035 Nigeria/Gwantu |  | | Journal (issue) | | .......................................... 39 Nigeria.................................................. Israel; Tom Cushman, Madagascar; Linus Adie, Nigeria; Bill Larson, USA; Veronica Shkarina, Moscow, Russia;...of the world’s only source of ametrine, a unique quartz variety that combines the purple color of amethyst...inexhaustible. Quartz varieties alone include amethyst, citrine, rose quartz, Lemurian quartz, and green-gold...green-gold quartz, while Bahia state to the north produces good quality amethyst and citrine. Amethyst is |  | | Journal (issue) | | “Soufflé” freshwater cultured pearls • “Churrasco quartz” from Brazil • Cat’s-eye rhodonite • Large H-rich...Spring 2006 “Paraíba”-type Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting by LA-ICP-MS...infrared (FTIR) spectrometer equipped with KBr and quartz beam splitters. A beam condenser (6×) was employed...Africa (Transvaal—30), Zambia (Kafubu—30), Nigeria (Gwantu—30), and China (Malipo—10). In addition, 66...678 0.396 Nigeria/Gwantu 1 Nigeria/Gwantu 2 Nigeria/Gwantu 3 Nigeria/Gwantu 4 Nigeria/Gwantu 5 0.093 |  | | Report (issue) | | Dietmar Schwarz and Gaston Giuliani Africa: Egypt, Nigeria, Tanzania, . . . . . . . . .52 Mozambique, Zambia...fantasy: even colorless crystal fragments such as quartz combined with green glue and disguised with a bit...with the free growing emeralds from Colombia, Nigeria and Afghanistan. According to the skill (or lack...lenticular vugs, druses, miarolitic cavities or quartz lenses. 18 While aquamarine and other pegmatite...Pegmatite Vugs (e.g., Kaduna, Plateau States, Nigeria) The mineralizations of the Kaduna and Plateau Provinces |  | | Journal (issue) | | located in Tanzania in 2005 (Laurs, 2006), while Nigeria developed into an important source for pink tourmaline...cuprian tourmaline was discovered near Edeko, Nigeria, though this material did not have quite the same...International: New find of pink-to-red tourmaline in Nigeria. G&G, Vol. 45, No. 4, p. 305. Laurs B.M., Zwaan...192–215. Smith C., Bosshart G., Schwarz D. (2001) Nigeria as a new source of coppermanganese-bearing tourmaline...Brazil as well as new sources in Mozambique and Nigeria. In cultured pearls, Chinese products have come |  | | Journal (issue) | | and Vietnam), Africa (Tanzania, Kenya, Zimbabwe, Nigeria, and Namibia, as well as Madagascar), South America...from southern Tanzania; spessartine garnet from Nigeria and Namibia; exceptional peridot from Pakistan;...Pakistan; and pink to red tourmalines from Nigeria and Brazil. Diamond was mined in northern Canada for the first...jade [both jadeite and nephrite], opal, peridot, quartz, spinel, tanzanite, topaz, and tourmaline). Locality...cutting and reexport). The African sources were Nigeria, Mozambique (figure 3), Zambia, and Madagascar |  | | Journal (issue) | | This case shows his sub-collections of calcite, quartz, pyrite and hematite, one species per shelf. Wilson...brass/gold-colored strips. 30 Figure 33. Fluorite on smoky quartz, 2.6 cm, from Frunthorn, Lake Zervreile, Grishun...and Erica Van Pelt photo. Figure 42. Elbaite with quartz, 2.7 cm, from Sakhan-Gyi, Mogok Stone Tract, Burma...Figure 45. Chrysoberyl twin grown around a colorless quartz crystal, 2.6 cm, from Santa Teresa, Espirito Santo...Aquamarine crystal, doubly terminated on smoky quartz, 2.7 cm, from the Erongo Mountains, Namibia. Wendell |  | | Journal (issue) | | loose single crystals and on a matrix of smoky quartz and cleavelandite feldspar. Some of the tourmalines...the imitations consisted of beryl (pale green), quartz (colourless) and glass (green and colourless)....associated with a variety of minerals, such as quartz, calcite, feldspar, garnet and topaz (Nassau &...been recovered. (a) Emeralds occur in a matrix of quartz and brownish mica (see hand for scale); image taken...containing beryl were still embedded in a white quartz-rich host rock and/or encrusted with brownish mica |  | | Book | | mineral aggregates, including large crystals of quartz, feldspar, mica, and beryl. Because pegmatite is...Greisen is a granitic (granite-like) rock formed from quartz and mica, while schist is a flaky stone characterized...these emeralds are typically found in calcite or quartz veins, not in schist. You may be familiar with...glassy (vitreous) sheen. Emerald, obsidian, and quartz, along with many other minerals, are subject to...r Calcite r Fluorite r Apatite r Orthoclase r Quartz r Topaz r Corundum (rubies and sapphires) r Diamond |  | | Book (edition) | | very old origin, often without lrnown source. e.g. quartz or cinnabar. Current practice most often names...polished mineral surface, expressed in clase. 7 - quartz. 8 - topaz, 9 - corundum, 10 - dia- percentage...purine-porphyrine group). a nickel porphyrine. With quartz. rutile, piemontite, sursassite, ardennite, Triclinic... translucent, luster growing on orthoclase and quartz on the Malosa resinous.streak white. H = 5. D =...where inclusions of aerinite cause blue color of quartz crystals, all Spain. With scolecite and prehnite |
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