 | | Report (issue) | | Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O Oxy-dravite Crystal Data: Hexagonal. Point Group: 3m. As prismatic...2001(1) Z=3 X-ray Powder Pattern: Osarara, Narok district, Kenya. 2.963 (100), 3.483 (84), 2.576 (68)...(1) 8.56 2.65 0.10 [2.65] 101.58 (1) Osarara, Narok district, Kenya; average of 10 electron microprobe...Series: Oxy-dravite is related to oxy-schorl, oxy-chromium-dravite, oxy-vanadium-dravite, and povondraite...muscovite. Distribution: From Osarara, Narok district, Kenya. Name: As a dravite with Al3+ + O2â â Mg2+ + |  | | Journal (article/letter/editorial) | | 1007/s00269-015-0743-z ORIGINAL PAPER Spectroscopy of red dravite from northern Tanzania Michail N. Taran1 · M. Darby...Springer-Verlag Berlin Heidelberg 2015 Abstract Low-Fe dravite with a formula of Na0.66Ca0.16 Mg2.62Fe0.33Mn0...Sambu may be found to be marked as belonging to Kenya, but in reality, it is located near the border in...distinctly different from the red dravite from the Osarara, Narok district, in Kenya that was formerly studied...heat treatments for color enhancement. Keywords Dravite · Tourmaline · Optical spectroscopy · Mössbauer |  | | Journal (article/letter/editorial) | | Mineralogist, Volume 98, pages 1442â1448, 2013 Oxy-dravite, Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O, a new mineral...50007, SE-10405 Stockholm, Sweden 2 Abstract Oxy-dravite, Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O, is a new...of Osarara (Narok district, Kenya) and occurs in quartz-muscovite schist. Crystals of oxy-dravite are...of 3.073 g/cm3. In plane-polarized light, oxy-dravite is pleochroic (O = orange and E = pink) and uniaxial...uniaxial negative: Ï = 1.650(5), Δ = 1.620(5). Oxy-dravite is rhombohedral, space group R3m, with the unit-cell |  | | Journal (article/letter/editorial) | | single-crystal neutron diffraction study of oxy-dravite G. D. GATTA1,*, F. BOSI2,3, G. J. MCINTYRE4 1 2...neutron diffraction study of oxy-dravite from Osarara (Narok district, Kenya) was performed. Intensity data...measured by infrared spectroscopy. K EY WORDS : oxy-dravite, tourmaline, crystal chemistry, neutron Laue diffraction...multi-methodological study on oxydravite from Osarara (Narok district, Kenya), based on single-crystal X-ray diffraction...spectroscopy (UV/VIS). The empirical formula of the Osarara oxy-dravite is as follows: X (Na0.83&0.15K0.02)S1.00 |  | | Journal (article/letter/editorial) | | tourmaline: Al-Mg disorder in the crystal structure of dravite FuNr C. HawrrroRNE, DANrnr, J. M.q'cDoNALD' Pnrnn...The crystal structure of a dravite (tourmaline) sample from Osarara, Narok District, c : 7.214(\ L, V:...V: 1589.0(6)L', R3m, has beenrefinedto an R Kenya,a : 15.947(2), index of 2.00/obased on 1136 reflectionsmeasuredwith...Here we present a crystal structure refinement of dravite and examine mean bondlength constituent-cationradius...Mattson and Rossman(1984, Sample 1, from Osarara, Narok District, Kenya, archival code NMNH no. 126030from |  | | Report (issue) | | Dravite NaMg3 Al6 (BO3 )3 Si6 O18 (OH)4 c 2001 ° Mineral Data Publishing, version 1.2 Crystal Data:...north of Perth, Western Australia. At Osarara, Narok district, Kenya. From Gujarkot, Nepal. Increasingly |  | | Journal (article/letter/editorial) | | (H2O) Mammoth-Saint Anthony mine, Tiger, Pinal County, Arizona, USA (32Âș42â23ââN 110Âș40â59ââW) Anthony...Department, Natural History Museum of Los Angeles County, Los Angeles, California, USA, catalogue numbers...collections of the Natural History Museum of Los Angeles County, Los Angeles, California, USA, catalogue numbers...West Sunday mine, Slick Rock district, San Miguel County, Colorado, USA Anthony R. Kampf*, Joe Marty, Barbara...collections of the Natural History Museum of Los Angeles County, Los Angeles, CA 90007, USA, catalogue numbers |  | | Journal (article/letter/editorial) | | 91125-2500, U.S.A. ABSTRACT The optical spectra of dravite (tourmaline) with an unusually high ratio of Fe3+...red ferrian dravite from Kenya are presented. Because about 90% of the iron in this dravite is Fe3+, the...colored dark-red crystal of dravite from Osarara, Narok District, Kenya (U.S. National Museum of Natural...and FIGURE 1. Polarized spectra of red ferrian dravite at ambient temperature and pressure. The sample...curve-fitting of the E^c polarized spectrum of ferrian dravite measured at 297 and 600 K. low temperature (Schugar |  | | 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...from Tanzania 96 Red Dravite Tourmaline from the Narok District, Kenya 99 Uvite-Dravite Chrome Tourmaline...Appendix B. East African Gemstones in the Los Angeles County Museum of Natmal History Collections 138 Appendix |  | Ertl, Andreas, Baksheev, Ivan A., Giester, Gerald, Lengauer, Christian L., Yu. Prokofiev, Vsevolod, Zorina, Lidiya D. (2016) Bosiite, NaFe3+ 3(Al4Mg2)(Si6O18)(BO3)3(OH)3O, a new ferric member of the tourmaline supergroup from the Darasun gold deposit, Transbaikalia, Russia. European Journal of Mineralogy, 28 (3) 581-591 doi:10.1127/ejm/2016/0028-2540 | Journal (article/letter/editorial) | | by a second generation of oxy-dravite and a third generation of dravite. Bosiite also coexists with quartz...ZAl4 â ZFe3+4. Further, bosiite is related to oxy-dravite, ideally Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O,...Fe-bearing dravite in Darasun, whereas in the Western Carpathians it evolved from schorlâdravite to povondraite...of a new tourmaline (recently described as oxy-dravite by Bosi & Skogby, Fig. 1. Black bosiite aggregates...supergroup Fig. 2. Photograph of bosiite and oxy-dravite from the Darasun gold deposit (ïŹeld of view ~3Ă4 |  | Bosi, Ferdinando, Reznitskii, Leonid, HĂ„lenius, Ulf, Skogby, Henrik (2017) Crystal chemistry of AlâVâCr oxy-tourmalines from Sludyanka complex, Lake Baikal, Russia. European Journal of Mineralogy, 29 (3) 457-472 doi:10.1127/ejm/2017/0029-2617 | Journal (article/letter/editorial) | | Cr-bearing goldmanite, eskolaiteâkarelianite, dravite, Vand Cr-bearing titanite, Cr-bearing rutile, ilmenite...vanadio-oxy-dravite; V-oxy-Cr-drv = vanadio-oxy-chromium-dravite; Oxy-V-drv = oxy-vanadium-dravite. O OH...classiïŹed as vanadio-oxy-dravite, oxy-vanadiumdravite, vanadio-oxy-chromium-dravite and chromo-alumino-povondraite...site as demonstrated by the vanadio-oxychromium-dravite compositions. Compared to Al, V3ĂŸ prefers the Y...Al the Z site) as observed in the vanadio-oxy-dravite samples. The comparison between Cr3ĂŸ and Al shows |  | | Journal (article/letter/editorial) | | temperature magnetic susceptibility study of a Kenyan dravite with 3.36 wt percent Fe. The M6ssbauer spectrum...encountered in tourmaline. Unusual red tourmalines from Kenya were reported to contain only trace amounts of transition...code Osarara, Narok District Kenya Kenya NMNH # 126030 CIT # 13764 CIT # 13765 NMNH 1 Dravite red...red 2 Dravite red 3 Uvite 4 Dravite orangered red 5 Dravite red Brumado, Bahia, Brazil Diamantina...15053 6 Schorl yellow b 8 Schorl green c 9 Dravite brown ~ Cahuilla Mr., Riverside Co., California |  | | Journal (article/letter/editorial) | | induced cation redistribution in Feâbearing oxyâdravite and potential geothermometric implications Ferdinando...Berlin Heidelberg 2016 Abstract Iron-bearing oxy-dravite was thermally treated in air and hydrogen atmosphere...coordinated Y and Z sites, an Fe3+-bearing oxy-dravite sample was thermally treated in air or hydrogen... The Fe3+-bearing oxy-dravite of the present study was taken from oxy-dravite holotype material and was...refinement Crystal fragments of the heat-treated oxy-dravite (samples H2 and AIR) were selected for X-ray diffraction |  | | 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 (issue) | | Theorique et Instrumentale, 6, 127. 385 RED DRAVITE FROM KENYA By PETE J. DUNN, M.A., F.G.A., JOEL E. AREM...ago by one of the authors (J.S.) at Osarara, Narok District, Kenya. The deposit is located at 1° 34' S...analysis of this tourmaline indicates that it is a dravite with a high iron content. This analysis is presented...1. T h e material is probably a ferrous 386 dravite as the aluminium content is too high to allow any...such as was noted by Frondel et al. (1966). This dravite has some gem potential, a n d it is dark red, of |  | | Journal (issue) | | Occurrences of elbaite (Voi, Kenya), dravite (Osarara, Kenya) and uvite (Magadi, Kenya; Moshi and Gere vi Hills...(HĂ€nnitf al., 1981) as well as red dravite (Dunn, et al., 1975) from Kenya are described in gemmological literature...solid-solution-series between dravite and uvite (Schmetzer and Bank, 1977) dravite Na Mg3 Al 6 [(OH,F)(OH)3(B03)3...dravites from Tanzania (Gerevi Hills, Umba Valley) and Kenya (Kwale District, Tsavo Park, Lualenyi) as well as...investigations proved the samples to be chromiferous dravite-uvite mixed crystals with slight excess of uvite |  | | Book (edition) | | JMPS MM MP NJMA ZRMO Republic province prefecture county departement departamento ...19.99, 9.79, Chro1110-a/11111ino-povo11draite -dravite. 19.62, /J= 110°42', Z = 8. d: 9.3(10)- 9.1(10)-4... Morocco. AM 91, 2012. 1249-1270, 2006. Fluor-dravite NaMg 3AllFl(OH) 3l(B0 3) 31Si6O1J Fluorbritholite-(Y)...4.2(7) - 4.0(7)- 2.97(10) 2.04(8). Similar to dravite,. brown, blackish brown to France black, transparent...quartz-diopside metamorphic rocks of the Oxy-chromium-dravite NaCrJCCr4 Mg 2)[0l(OH) 3 J(BO3) 3ISi6O1s] Slyudyanka |  | | Book | | brownish crystals. In a greenish-blue aquamarine from Kenya, albite, spessartine and euhedral green tourmaline... but the trace element composition of Burmese, Kenya, Chatham, Verneuil, Kashan and Knischka stones (the...violet crystals are found in Maine (Androscoggin County), USA and formerly at Ehrenfriesdorf, Saxony, East... A golden-green variety has been reported from Kenya and chatoyant yellow and blueâgreen stones have...most material coming from the Champion Mine, Mono County, California, USA where it occurred in an andalusite | | | Book | | brownish crystals. In a greenish-blue aquamarine from Kenya, albite, spessar,tine and euhedral green tourmaline... but the trace element composition of Burmese, Kenya, Chatham, Verneuil, Kashan and Knischka stones (the...violet crystals are found in Maine (Androscoggin County), USA and formerly at Ehrenfriesdorf, Saxony, East... A golden-green variety has been reported from Kenya and chatoyant yellow and blue-green stones have...most material coming from the Champion Mine, Mono County, California, USA where it occurred in an andalusite |  | | Journal (issue) | | miners, such as this tsavorite miner near Voi, in Kenya, are estimated to supply some 80% of the worldâs...not treated, such as this 3.47 ct tsavorite from Kenya, were in high demand throughout the decade. Courtesy...been linked to the 1998 U.S. Embassy bombings in Kenya and Tanzaniaâhad sold tanzanite to fund terrorism...demantoid (figure 6). The Taita-Taveta region of Kenya (Coast Province, near Voi) produced colorchange...Winza [figure 11], as well as previous deposits), Kenya (John Saul mine and a new deposit at Baringo), India |  | | Book (edition) | | recorded, from Kentucky, and another from Rutherford county, North Carolina, a pale yellow flattened octahedron...was established in the area of Murfreesboro, Pike county, Arkansas, where three types of igneous rock are...and, most unusually, in situ, near Wutu, Changle county, central 142 Australia Shandong Province. The...sapphire-bearing rock of Yogo Gulch, Judith Basin county. The first report of the occurrence was published...Carolina ruby of fair quality has been found in Macon County, at Cowee Creek. Ruby crystals are found in gravels |  | Gaines, Richard V., Skinner, H. Catherine W., Foord, Eugene E., Mason, Brian, Rosenzweig, Abraham, King, Vandall T. (1997) Dana's New Mineralogy (8th ed.) Wiley-Interscience. p.1872 | Book (edition) | | luster. strongly pleochroic and anisotropic. Norton County enstatite achondrite and Quizhen enstatite chondrite...weathering product of caswell5), silverite in the Norton County enstatite achondrite. BM AM 70:638(198 ABI:465...mineral collection she donated to the Los Angeles County Museum of Natural History. Wickmanite group. TET...lowaite N, = 1.557; 2V = 24°. From Scawt Hill, County in vugs in a larnite rock, with afwillite, portlandite...phlogopite, graphite, corundum, tremolite, norbergite, dravite, and so on, especially at Edenville and Warwick |
|
