 | | Journal (article/letter/editorial) | | R*CKWOOD** Division of Geological Sciences, University of Cape Town 12,eceived November 4, 1969 Abstract. Brief...in the kimberlites of Lesotho, Rhodesia, Sauth Africa, and Tanzania. Six new mineral assemblages, which...ibole; garnet-spinel; garnet-clinopyroxene-quartz; garnet-clinopyroxene-high sanidine; garnet-clinop...derived. The physical properties (n and a0) of garnet from 136 peridotites and pyroxenites have indicated...(uvarovite -~ andradite). Similar measurements of garnet from 57 eclogitic rocks have enabled us to locate |  | | Journal (article/letter/editorial) | | Kaapvaal block, where the classical mines in the Kimberley region are located. The most striking difference...is the relative paucity of low-Ca (<2 wt% CaO in garnet) harzburgites and a low ratio of harzburgitic to...GeoScience Centre, De Beers Consolidated Mines, PO Box 82232, 2135 Southdale, South Africa P. McDade Department...re-enrichment but the trace element signature of garnet inclusions is not in favor of strong enrichment...mines the majority of lherzolitic and harzburgitic garnet inclusions are characterized by moderately sinusoidal |  | | Journal (article/letter/editorial) | | n d Geochemistry, University of Cape Town, Rondebosch, South Africa Received May 13, 1968 Abstract. The...collection which is stored a t the University of Cape Town. E v e r y suitable sample available to the...authors has been examined. A gap in the range of garnet volume percentages occurs in the samples studied...d 30 %. Garnet peridotites characteristically have < 15 % garnet and eclogites > 30% garnet. Very rare...orthopyroxene. All b u t two of the peridotite-pyroxenite group contain orthopyroxene. The garnets from the peridotites |  | | Journal (article/letter/editorial) | | overlap with the record established from cratonic garnet peridotite xenoliths and xenocrysts but reflect...indicate polybaric melt extraction proceeding from the garnet into the spinel stability fields, most readily explained...mineralogical layers, spinel facies (lilac) and garnet facies (purple to pink). Small volume melt fractions...inclusion-bearing diamonds from the mines of South Africa and Botswana was begun by Gurney and Harris...diamonds is not known. In early work (1973–1985) run-of-mine diamonds in the sieve class −6 + 5 (1.83 mm aperture |  | | Book | | Kimberlites are consequently of interest to a diverse group of earth scientists, ranging from isotope g~ochemists...Project of Energy, Mines, and Resources, Canada; and De Beers Consolidated Mines are acknowledged for financial............................... 126 5.3.3.2. West Africa ........................................... 126............ .................... 6.4.3. Pyroxene-Garnet Intergrowths (Paragenesis 3) . . . . . . . . ..... . . . . . . . . . . . . 6.4.9. Orthopyroxene-Garnet Intergrowths ................................ 6 |  | | Journal (article/letter/editorial) | | Article Crystal Structure of an Anisotropic Pyrope Garnet That Contains Two Cubic Phases Sytle M. Antao Department...different samples of pyrope garnet, ideally Mg3Al2Si3O12, from South Africa was refined using the Rietveld...Rietveld method, space group Ia3d, and monochromatic synchrotron high-resolution powder X-ray diffraction...diffraction (HRPXRD) data. Sample 1 from Wesselton Mine is a single cubic phase and is optically isotropic. Electron-probe... and Si-O = 1.6343(3) Å. Sample 2 from De Beers Diamond Mine has an average composition {Mg2.33Fe2+ 0 |  | | Book | | Jacques P. Cassedanne Universidade Federal do Rio de Janeiro For his valuable participation in research...Angeles American Museum ofNatural History - New York De Beers Consolidated Mines Naturhistorisches Museum -...the Cruzeiro tourmaline and mica mine and the Jacobina amethyst mine. He owns several other mines as well...Jarge chain of retail stores, centered in the Rio de Janeiro area, but located in other Brazilian cities...Bahia state, and from Rio and Sao Paulo further South, the pioneers made their way to the Jequitinhonha |  | | Book | | with whose research groups at the universities of Cape Town and Chicago I have had long and fruitful collaboration...southern Africa has been carried out with the cooperation and assistance of the geologists of De Beers Consolidated...7.3 2.8 2.9 Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Africa . . . . . . .... . . . . Central Africa. . . . . . . . . . . . . . . . . . . . . . . East Africa. . . . . . . . . .... . . . . . . . . . . . . . . . Southern Africa . . . . . . . . . . . . . . . . . . . . . U.S.S.R. . |  | Banas, A., Stachel, T., Phillips, D., Shimizu, N., Viljoen, K.S., Harris, J.W. (2009) Ancient metasomatism recorded by ultra-depleted garnet inclusions in diamonds from DeBeers Pool, South Africa. Lithos, 112. 736-746 doi:10.1016/j.lithos.2009.04.043 | Journal (article/letter/editorial) | | recorded by ultra-depleted garnet inclusions in diamonds from DeBeers Pool, South Africa A. Banas a,⁎,1, T. Stachel...Box 524, Auckland Park, 2006, Johannesburg, South Africa e Division of Earth Sciences, University of...Paleoarchean Nb anomaly a b s t r a c t Peridotitic garnet inclusions in diamonds from the DeBeers Pool mines...extremely depleted mantle source. A large number of garnet inclusions have CaO contents of less than 1.8 wt...in the protolith for the cratonic root beneath Kimberley (Kaapvaal Craton) exceeded orthopyroxene exhaustion |  | | Book | | ILLUSTRATIONS PAGB ........ KimlDerley, Soutli Africa, workings Kaffir employees Diamond Mines: Open...machines at Kimberley. Diamond pulsator at De Beers Diamond Mines, Kimberley, South Africa Railway One...One 32 ... 34 Kimberley Mines 36 to Kimberley, South Africa day's diamond wash at the The tunnel...one-thousand-foot Beers Diamond Mines Cullinan Diamond — in the rough; actual De 38 size . ......xiv PAOB Garnet crystals, and pebbles of Pyrope. Sapphires. Diamond crystals from Kimberley Mines National |  | | Book (edition) | | Ercit (Canada). Alexander Falster (USA). Jeffrey de Fourestier (Canada). Robert Gault (Canada), Joel...Minerals that are listed as belonging to the same group are similarly closely comparable in composition...\lim•ra/ogica ASG ASJS,\' Arc:hil-1.•s de Science G,•111.½·e Atti de/la Sod,•ta ltalicma di Scienze Natura/i...1·exactas,jisicos y natura/es. Unil'ersidad nacicmal de Cordoba Bulletin of the Geologica/ Society of Finland...Geo/ogical Sciences Bulletin de ,\lineralogie and its precursors Boletin de Minera/ogia (Sociadad Mexicana |  | | Book | | Sapphire Chrysoberyl, Topaz and Spinel Beryl The Garnet Group Tourmaline and Zircon Quartz, Agate and Chalcedony...gravel C. Corundum group D. Chrysoberyl and spinel E. Beryl group F. Garnet group G. Topaz and tourmaline...tourmaline H. Zircon I. Quartz group J. Opal K. Chalcedony group L. Jade minerals M. Lapis lazuli... The ‘Big Hole’ at Kimberley za. Underground working at Premier Diamond Mine zb. Grease tables at...Premier Mine 3. Removing the overburden covering diamondiferous gravels on coast of South West Africa II |  | | Journal (issue) | | of the elegant jewels favored by the distinctive group known as the Edwardians, who reigned as the leaders...MA; Anthony de Goutiere, Victoria, BC, Canada; Douglas P. DeHaven, Paris, TX; Folkert H.'De Jong, Victoria...Grishlzo, St. Petersburg, FL; Sue Angevine Guess, De Land, FL; Phyllis M. Gunn, Spokane, WA; Helen Haddy...CA; Jerry L. Holt, Kodiak, AK; Harold E. Holzer, Cape Coral, FL; P. Horninge, Amsterdam, Netherlands;...H. Stevens, Gansevoort, NY; M. Deloris Stevens, Cape Coral, FL; Dee Stodghill, Houston, TX; Helen E. |  | | Journal (issue) | | Harry A. Horwitz M. A. Huebler John Hummel Renata de Jara Joseph's Jewelers A. Kalokerinos J. K. Kalkhorst...such as tanzanite, ruby, fancycolored sapphire, garnet, and tourmaline; to date, more than 50 gem species...varieties have been produced. As the 1990s begin, De Beers has reinstated diamond exploration in Tanzania...HISTORY Hominid habitation in this part of East Africa has been documented back to about 6 million years...d a n d chiefs)and established the German East Africa protectorate; following World War I, this became |  | | Book (edition) | | Albert Museum, and the Imperial Institute, all at South Kensington. Many of the examples referred to in...the British Museum of Natural History, also at South Kensington. NOTE TO SECOND EDITION A few minor... • - - 177 - - 187 ' X¥IIL The Quartz Group - *- - • XX." Jade (Nephrite and Jadeite) ...Abandoned Open Workings of the Kimberley Diamond Mine at Kimberley, South Africa - IV. {a) Crystal of Diamond...manufactured commercially. Uvarovite or chrome-garnet owes its green colour to chromium which is here |  | | Book (edition) | | Classifications 84 85 Value of Gemstones 126 Tourmaline Group Fire Opal 168 . | 85 Description of Gemstones...Tiger’s-Eye 140 Chalcedony 142 142 see 142 oo 120 Garnet Group ie ‘ 176 Zoisite Species Tanzanite 176 Prasiolite...Anyolite 176 : 178 Hematite . 178 Pyrite 180 Feldspar Group Amazonite Moonstone 180 180 Orthoclase 180 Labradorite...jewelry, include amethyst, rock crystal, amber, garnet, jade, jasper, coral, lapis lazuli, pearl, serpentine...center below “Cullinan II." (or “Lesser Star of Africa’) with 317.40ct. It is the second-largest polished |  | | Journal (article/letter/editorial) | | Grolog~. of Capr Town. Rondehch University 7700. South Africa of Glas,yo~v, Glu.s,qo~ GIZ XQQ. UK Received...1997 Elsevier Scienbe B.V. Keword.vc diamond; garnet group; peridotites: mantle; cratons: Siberia 1...Siberian craton 370 Ma ago [IO,1 31. The Udachnaya mine is the largest Russian producer of gem diamonds...source are overwhelmingly peridotitic [ 151. Purple garnet inclusions were extracted from 200 Udachnaya diamonds...composition from subcalcic garnet htizburgites to calcium-saturated garnet lherzolites 11611.In con- |  | | Book | | e SEVENTH INTERNATIONAL KIMBERLITE CONFERENCE Cape Town, April 1998 EXTENDED ABSTRACTS All extended...responsibility for authors’ errors and omissions. SOUTH AFRICA SEVENTH INTERNATIONAL KIMBERLITE CONFERENCE...SPONSORS BHP Diamonds Inc. De Beers Consolidated Mines SPONSORS Bateman Group (including Bateman Process...Trans Hex Group Ltd CONTRIBUTORS Council for Geoscience (Geological Survey of South Africa) SouthemEra...Ltd SOCIETY SPONSORS Geological Society of South Africa (GSSA) The International Association of Geochemistry |  | | Journal (article/letter/editorial) | | February 2009 Editor: R.W. Carlson Keywords: subcalcic garnet Archean mantle Kaapvaal craton Lu–Hf Sm–Nd depletion...t Twenty four subcalcic garnets from the Finsch mine (SA) were analysed for major and trace elements...were able to distinguish two groups of garnets: group-1 with low Cr# (b 11.4), which correlates negatively...negatively with CaO and positively with (Lu/Er)N and group-2 displaying high and variable Cr# (10.9–34.3) but...findings imply that group-1 garnets were mainly generated by depletion in the garnet and group-2 garnets by |  | | Book | | right angles to each other. ISOMETRIC I / l h- garnet spinel (icositetrahedron) (octahedron) Three...almandine garnet although these may fade with time. can produce colour changes, A group including...of the stone for a red ray, which is refracted garnet is moderately magnetic and can be least, and a...Almandine garnet Mineral name Dispersion Cubic zirconia 0.065 Spessartine garnet Demantoid garnet 0.057...MODERATE Demantoid garnet Peridot Pyrope garnet Dark green tourmaline Hessonite garnet WEAK Brown sinhalite |  | | Book (volume) | | Uytenbogaardt and E. A. J. Burke. (64839-7) $11.95 De Re Metallica, Georgius Agricola. (60006-8) $15.95...chemical classification. Thus Bauer was able to group together gem minerals which are related chemically...found at the p. 127, line 5. Premier Mine, Transvaal, South Africa. It weighed 3106 carats in the rough...production and almost 56% of world annual production. South Africa is p. 159, line 17. ; ADDENDA Vlll (1968)...stones of smaller sizes. South Africa diamonds Congo Other large producers in Africa are is still the major |  | | Book (edition) | | Wood 148 Orthoclase 164 Spinel 100 Topaz 102 Garnet 104 Pyrope 104 Almandine 104 Uvarovite 106 Zircon...jewelry, include amethyst, rock crystal, amber, garnet, jade, jasper, coral, lapis lazuli, pearl, serpentine...center below "Cullinan II." (or "Lesser Star of Africa") with 317.40ct. It is the seconddiamond in the...Stones, in short CIBJO (Confederation Internationale de la Bijouterie, Diamants, Perles, et Pierres). Certainly...Arkansas diamond Balas ruby Pyrope Red or green garnet Rock crystal Blue alexandrite Pink spinel Blue |  | | Report (issue) | | Uses .... Occurrence Industry and Marketing . Garnet .... Introduction . Uses .... Grades .... Occurrence...pur poses. They are obtained from Brazil and South Africa. (iii) Carbonado—black diamond or carbon, is...1721 and 1870, but the present yield is small. Africa now produces over 95 per cent, of the world’s diamonds...recent years, however, the alluvial deposits of Africa have become more important. The annual value of...Coast, Seirra Leone, Angola, Union of South Africa and South-West Africa. In the United States of America |  | | Catalog/List | | RAINBOW OF AFRICA GEM & MINERAL COLLECTION Front Cover: Gems from the Rainbow of Africa Collection... Heritage Signature® Auction #5236 The Rainbow of Africa Collection Gems & Minerals October 15, 2015 | New...Signature® Internet Session 2 Heritage Auctions Design District Annex 1518 Slocum Street • Dallas, TX 75207 (HERITAGELive...RAINBOW OF AFRICA COLLECTION You have in front of you our presentation of the Rainbow of Africa Collection:...The mineral riches of Africa are not the only things making up the Rainbow of Africa Collection. For the |  | | Book (edition) | | years after Church’s letter appeared in print, the South African diamond rush was in full spate, and 5000...sprung up around the site of the De Beers farm was formally named Kimberley after the British Secretary for...for the Colonies, the Earl of Kimberley. In 1877, the French chemist Edmond Frémy manufactured the first...identification of a new gem variety, green demantoid garnet. One of many disturbing events in the jewellery...mound of ruby powder in a flame. Meanwhile, in South Africa, Cecil Rhodes and Barney Barnato had finally |
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