 | | Journal (issue) | | counterparts of natural basaltic bluish-violet and yellow sapphires. Other synthetic sapphires are coloured...market in 1993 (Peretti and Smith, 1993, 1994) and yellow, orange, bluish-green and blue synthetic sapphires...the presence of various amounts of chromium. In yellow, green, bluegreen and blue samples, only traces...â˘;:⢠j j t e t o 8 * Fe^/tte * yellow Fe^ minor light yellow yellow crystal (l)[b] yellowishgreen...basaltic type bluishviolet sapphire nat: basaltic type yellow sapphire imit: green sapphire imit: ! padparadscha |  | | 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) |  | | Book | | noted gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical...diamond mine, known for Yeryfine, rare, pink diamonds. Emerald, alexandrite, garnet, and tourmaline are all...interest. Rare and unusual garnet and chrome tourmaline are widely identified with the region. ( continuedon...of "collector'' stones including a 27.03-carat yellow scapolite, a 7.02-carat purple scapolite, a 34...69-carat chrome tourmaline. Courtesy of the 'Irelawney Collection of the Los Angeles County Museum of Natural |  | | Journal (issue) | | of the pearl surfaces. The picture shows a bead (yellow, width 6.5 mm) in comparison with pearls produced...Magnified 70Ă. 6c Figure 8: A cluster of brownish yellow platelets, probably mica, is an inclusion in a...studied. Of the two non-precious opals, one is pale yellow brown, while the other is dark brown with a reddish...are opaque. Of the nonprecious opals, the pale yellow opal is nearly transparent, while the dark brown...features as described below. Strongly decomposed pale yellow-brown soft tuff particles and plagioclase crystals |  | | Journal (issue) | | XVII N o . 7 JULY 1981 GOLDEN YELLOW TOURMALINE OF GEM QUALITY FROM KENYA By HENRY A. HĂNNI, Ph.D., F...the Research of Gemstones, Zurich, Switzerland. Yellow and brown tourmalines are mainly reported from...attractive golden yellow colour appeared in the trade, originating from Voi-Taveta area, Kenya. Although the...results proved the tourmalines to be members of the dravite-uvite series with a ratio of 78:22. ISSN: 0022-1252...partial microprobe analyses of yellow tourmalines from Kenya (Voi-Taveta) TABLE 1 ~ w (:) -J ~ :>< |  | | 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... 1997), and several examples of aquamarine and yellow heliodor, and very rarely emerald, have been seen...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 |  | | Report (issue) | | extraLapis English No. 3: Tourmaline Publisher Lapis International, LLC; East Hampton, CT Concept &...Golconda Mine in Minas Gerais, Brazil by Eberhard Equit, 1993 extraLapis English No. 3 Tourmaline A Gemstone...LAPIS INTERNATIONAL, USA Tourmaline ⌠History ⌠Mineralogy ⢠Tourmaline - History in Brief ..........Mineralogy of the Tourmaline Group . . . 10 Species by Species - The Minerals of the Tourmaline Group ........24 Ferdinand Damaschun ⢠Is There Really Black Tourmaline? ..... 30 Joachim Zang and Warde da Fonseca-Zang |  | | Journal (article/letter/editorial) | | of the ruby deposits of the Mangari area in SE Kenya A. Mercier a a,) , P. Debat a , John M. Saul ...sapphire.. The ruby deposits in the Mangari area of SE Kenya, are among the most productive and best known. Enclosed...reserved. Keywords: ruby deposits; Mozambique Belt; Kenya; ultrabasites; granulite facies 1. Introduction...present work concerns primary ruby deposits in Kenya and Tanzania especially those of the Mangari area...of the Tsavo West National Park Ĺ˝Fig. 1. in SE Kenya. East Africa Ĺ˝KenyaâTanzania. is endowed with primary |  | | Journal (article/letter/editorial) | | Tourmaline: The Kaleidoscopic Gemstone 7.7 carat fancy bluegreen Namibian tourmaline (set in 18 k gold)...top-quality âneonâ blue-to-green, copper-bearing tourmaline, the ParaĂba-type, is one of the highest-priced...metamorphic rocks are generally draviteâuvite species. KEYWORDS : tourmaline, gemstone, ParaĂba-type, chromophores...gem deposits TOURMALINE AS A GEMSTONE Perhaps more than any other gemstone, tourmaline is renowned for...within individual crystals (FIG. 1). In addition, tourmaline has the appropriate combination of beauty, durability |  | | Journal (issue) | | the Chivor emerald mine Bill Larson Gemstones and gem mining in San Diego County, California To book...from Pakistan|Chrome chalcedony from Tanzania| Yellow dravite from Tanzania|New garnets from East Africa|Quartz...includes reports on polymer-treated hessonite; yellow-green translucent opal; a large âcopperyâ-coloured...blue coloration, similar 186 to ParaĂba-type tourmaline. Rarely, this material shows chatoyancy (Kammerling...acquiring rough sphene (titanite) from the Darren mine located near AmbilobĂŠ in the Vohemar District of |  | | Journal (article/letter/editorial) | | 3749/canmin.49.1.301 A SURVEY OF Mn-RICH YELLOW TOURMALINE FROM WORLDWIDE LOCALITIES AND IMPLICATIONS... California 92008, USA Abstract Yellow to yellow-green tourmaline was analyzed from granitic pegmatites...and the Democratic Republic of the Congo. Yellow tourmaline is predominantly Mn-rich (> 3 wt.% MnO) elbaite...elbaite and âfluor-elbaiteâ. Though rare, yellow rossmanite and âfluor-rossmaniteâ from Mozambique also...09 wt.% FeO). Relative to typical pale-colored tourmaline, all have elevated TiO2 (average 0.28 wt.%). |  | | 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...bicolored tounnaline (12.90 ct), all from the Himalaya mine (California). Thestones were faceted by PalaInteri~ntional...most important producers of fine aquamarine, tourmaline, and topaz in the world today. With the award |  | | Journal (issue) | | XLIII WINTER 2007 CVD Synthetic Diamonds Canary Tourmaline WINTER 2007 Fluorescence Spectroscopy Napoleon...clarity. 314 pg. 295 Carat Points Yellow Mn-rich Tourmaline from the Canary Mining Area, Zambia Brendan...Alexander U. Falster Explores the vivid âcanaryâ yellow elbaite from the Lundazi District of eastern Zambia...Zambia, the most important source of this tourmaline. 332 Fluorescence Spectra of Colored Diamonds Using...Myanmar ⢠Cu-bearing tourmaline mines in Mozambique ⢠New Cu-bearing tourmaline from Nigeria ⢠Synthetic |  | | Journal (article/letter/editorial) | | Mineralogist Vol. 44, pp. 347-365 (2006) ZONED TOURMALINE ASSOCIATED WITH CASSITERITE: IMPLICATIONS FOR...H3A 2A7, Canada Abstract The composition of tourmaline in the San Rafael SnâCu lode, in southeastern...forms, colors and compositions of tourmaline, ranging from dravite to schorl, are present in the deposit...deposit, but the late tourmaline that accompanied deposition of early cassiterite has an unusual dark green...trend of enrichment in iron. Appearance of this tourmaline in the paragenesis coincided with a marked change |  | | Catalog/List | | Cerussites and Cuprites, Sapphires and Spinels, Tourmaline and Tanzanite, Emeralds and Jeremejevites, the...collection, a lot of it collected when the Tsumeb Mine (as well as other mines of the region) were still...engineering work took him to the Tsumeb Mine in Namibia. This mine is renowned for producing what are arguably... SESSION ONE MINERALS 57001 Azurite Level 8, Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia If the attachment...Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia Some of the best things to come from the Tsumeb Mine were |  | Henry, D. J., Novak, M., Hawthorne, F. C., Ertl, A., Dutrow, B. L., Uher, P., Pezzotta, F. (2011) Nomenclature of the tourmaline-supergroup minerals. American Mineralogist, 96 (5) 895-913 doi:10.2138/am.2011.3636 | Journal (article/letter/editorial) | | 96, pages 895â913, 2011 Nomenclature of the tourmaline-supergroup minerals Darrell J. Henry,1,* Milan...70803, U.S.A. Chairman of the Subcommittee on Tourmaline Nomenclature, Department of Geological Sciences...I-20121 Milan, Italy 2 aBstract A nomenclature for tourmaline-supergroup minerals is based on chemical systematics...systematics using the generalized tourmaline structural formula: XY3Z6(T6O18)(BO3)3V3W, where the most common...variability occurs at the X, Y, Z, W, and V sites. Tourmaline species are defined in accordance with the dominant-valency |  | | Journal (article/letter/editorial) | | tourmahne stability is iowered by about 60°C. Tourmaline may coexist with A~S~IUC~-AB the other MgD-AlrO&&SiQ-Ha...Thtinfrandgpcceumisintcrmodirttc between those of dravite and &aite. The common alkali and calcium deficiencies...the occupancy of (3a) it is significant that tourmaline lacking Na, Ca, and K can be synthesized in the...tourmalines the following structural formulae: of the tourmaline group is only gradually being understood. A simplified...N~e~A~(B03)~[S~O~*J(OH), and extending 1) towards dravite by virtue of the Mg - Feâ su~titution B Mg@QAlz |  | | Journal (issue) | | INSTITUTE OF AMERICA Method for Identifying Tourmaline Species Age Dating of Zircon Inclusions in Sapphire...2019 VOLUME 55, No. 1 EDITORIAL 1 Studies on Tourmaline, Sapphire, Cultured Pearl, and a Reliquary of...ARTICLES 2 A New Method for Determining Gem Tourmaline Species by LA-ICP-MS Ziyin Sun, Aaron C. Palke...simplified but comprehensive classification of gem tourmaline species based on quantitative measurement of...discovered in North America ⢠Chatoyant quartz/tourmaline doublet ⢠Faceted gahnospinel ⢠Glass bangles |  | | Journal (article/letter/editorial) | | California, San Diego] at 03:56 02 March 2016 What TOURMALINE Says T HIS IS THE SECOND OF SEVERAL ARTICLES...in which they form. The series continues with tourmaline, the most common of the boron-rich minerals....and habits of tourmaline: (a) left: schorl, 20 cm, Minas Gerais, Brazil, and right: dravite, 12 cm, Yinnietharra...cm, Garnet Ledge dike, Little Three mine, Ramona, San Diego County, California. Varieties of elbaite:...elbaite: (c) rubellite, 10 cm, Himalaya mine, Mesa Grande, California, found by Ralph Potter in 1958, William |  | | Journal (issue) | | world-wide locality index The localities are listed by county, followed by a listing of the most prominent minerals...pegmatite in Amelia County and the Lynch Station locality (turquoise crystals) in Campbell County, are now closed...(c) = currently closed to collecting ALBEMARLE COUNTY Alberene soapstone quarry-Alberene actinolite-tremolite...limonite pseudomorphs after pyrite, siderite Faber lead mine-near Faber cerussite, chalcopyrite, fluorite, argentiferous...rutile, spessartine, topaz, tourmaline, triplite Trueheart pegmatite mine (f)-near Amelia beryl (var. |  | | Report (issue) | | Grauch (1983) gave a description of regional and mine geology at Jabiluka; that paper provides the regional... Figure 3 shows the general stratigraphy of the mine sequence. T129V drill hole was drilled to a depth...coarse-grained muscovites and chlorites as large as 2 mm. Tourmaline-bearing pegmatite is the only recognizable igneous...SCHIST csur~~^Z.^ SERIES cs MC CSM cs CG cs MAIN MINE xx c CSM \ Cf> o c D 1C O o*"-^ c °0 0°...CS LOWER MINE SERIES 1 CS_____1 CS(B) CS cs LOWER SCHIST o c. rt 1 c. o i LOWER MINE SERIES 2 LOWER |  | | Journal (article/letter/editorial) | | world-wide locality index. The localities are listed by county, followed by a listing of the most prominent minerals...Alleghany County. Howard Freeland specimen and photo. Rutherford pegmatite in Amelia County and the Lynch...Station locality (turquoise crystals) in Campbell County, are now closed to collectors. However, landowners...(c) = currently closed to collecting Albemarle County Alberene soapstone quarryâAlberene amphiboie asbestos...pseudomorphs after pyrite, pyrite, siderite Faber lead mineânear Faber cerussite, chalcopyrite, fluorite, argentiferous |  | | Journal (article/letter/editorial) | | composition and coloring of tourmaline is discussed. It is shown that manganese tourmaline-tsilaisite is similar...similar to tourmaline-elbaite in composition and condition formation. The miscibility in the sherlite-elbaite-tsilaisite...but in the sherlite-dravite-tsilaisite system there is a gap between the dravite and tsilaisite, similar...relationship between dravite and elbaite. Manganese may be present in tourmaline in the form of Mn 2 +...+ and Mn 3+. The pink coloring of the tourmaline is caused by Mn 3+. This conclusion has been drawn from |  | | Journal (issue) | | colour change from green to red in chromiferous tourmaline from Nchongo in the Umba area (Figure 1) and...Figure 1: A green UE tourmaline turns red when placed on top of another green UE tourmaline. observed in other...this is based on a detailed study of Nchongo tourmaline, but first there is a review of previous investigations...change (in addition to strong pleochroism) is tourmaline. Bank and Henn (1988) reported change from green...century earlier by Cossa and Arzruni (1883). This tourmaline was found in chrome-iron deposits near Sysert |  | | Journal (article/letter/editorial) | | poor (<1%) heavy mineral suite consisting of tourmaline, rutile, garnet, staurolite, ilmenite, zircon...Ti (e.g., biotite), are subordinate. Over 512 tourmaline grains from seven outcrops in the MiechĂłw Segment... The majority of grains belong to the alkali tourmaline group in which the X-site is dominated by Na...to 0.9 apfu). Detrital tourmalines are mainly dravite with a prevalent schorl end-member with average...Their chemical composition suggests that most tourmaline grains were sourced from Al-rich and Al-poor |
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Yellow Tourmaline Mine, Taita-Taveta County, Kenya