 | | Journal (article/letter/editorial) | | The Somabula Forest Diamond Field Southern Rhodesia M. C. B The Somabula Forest diamond placers are...workings. The oldest mine of importance in the Somabula area is the Shamrock Gold Mine to the north of...for gold led to the discovery of diamonds on the Somabula Spruit in 1Ç)03 by H. R. Moir and his brother...other minerals associated with the diamonds at Somabula might be expected. PRODUCTION Value £27,843 3...331 2,991 2,230 3,083 1,917 GENERAL GEOLOGY The Somabula Forest and the surrounding country is underlain |  | | Journal (article/letter/editorial) | | mining for gold in the valleys of the J_ Cariboo district of British Columbia has led to a careful investigation...barriers of Glacial age. VII.—PLATINUM METALS IN THE SOMABULA DIAHONDIFEROTJS GBAVELSBr H. B. MAUFE. Southern...Geological Survey- Short Report No. 5, 1319. HE Somabula Diamondiferous Gravels which contain the diamond...occurrence of platinum in Southern Rhodesia, said: "The Somabula gravel for instance is a likely source, since...of chromite rock are abundant, and many of the chalcedony pebbles can be recognized by the practised eye |  | | Journal (article/letter/editorial) | | mining for gold in the valleys of the J_ Cariboo district of British Columbia has led to a careful investigation...barriers of Glacial age. VII.—PLATINUM METALS IN THE SOMABULA DIAHONDIFEROTJS GBAVELSBr H. B. MAUFE. Southern...Geological Survey- Short Report No. 5, 1319. HE Somabula Diamondiferous Gravels which contain the diamond...occurrence of platinum in Southern Rhodesia, said: "The Somabula gravel for instance is a likely source, since...of chromite rock are abundant, and many of the chalcedony pebbles can be recognized by the practised eye |  | | Journal (article/letter/editorial) | | mining for gold in the valleys of the J_ Cariboo district of British Columbia has led to a careful investigation...barriers of Glacial age. VII.—PLATINUM METALS IN THE SOMABULA DIAHONDIFEROTJS GBAVELSBr H. B. MAUFE. Southern...Geological Survey- Short Report No. 5, 1319. HE Somabula Diamondiferous Gravels which contain the diamond...occurrence of platinum in Southern Rhodesia, said: "The Somabula gravel for instance is a likely source, since...of chromite rock are abundant, and many of the chalcedony pebbles can be recognized by the practised eye |  | | Report (issue) | | ZIMBABWE GEOLOGICAL SURVEY BULLETIN No. 90 The Erosion Surfaces of Zimbabwe L. A. LISTER, M.Sc., D.Phil...LIBRASÏ ZU - 06.01 Ölungen ïte Cstteilands 72& ZIMBABWE GEOLOGICAL SURVEY BULLETIN No. 90 iSRiC LIBRARY...Wagentngen, The Netherlands The Erosion Surfaces of Zimbabwe L. A. LISTER, M.Sc, D.Phil. ISSUED BY AUTHORITY...the erosion surfaces of Zimbabwe. She has lectured at the University of Zimbabwe since 1963 and this Bulletin...earlier authors had postulated. Cainozoic tilting in Zimbabwe, which raised the eastern margin of the country |  | | Journal (article/letter/editorial) | | few of the intensely sheared rocks of such a district, except very locally--a few yards, for instance...Rifle Kopje, near Bulawayo; Red Hills, Victoria district). In other cases they occur as well-marked dykes...sequence. I t is in the somewhat remote Lomagundi district that these beds have attracted most attention...beds in the course of two lengthy visits to the district, and have recently paid i I have to express my...present day, which are intrusive. In the Abercorn district, also in Northern ]Kashonaland, and possibly on |  | | Journal (issue) | | Update on Emeralds from the Sandawana Mines, Zimbabwe J.C. (Hanco) Zwaan, Jan Kanis, and Eckhard J.... UPDATE ON EMERALDS FROM THE SANDAWANA MINES, ZIMBABWE By J. C. (Hanco) Zwaan, Jan Kanis, and Eckehard...is believed by some that the area now known as Zimbabwe was the fabled land of Ophir, which produced gold...contributed to emerald formation in this part of Zimbabwe, but it also offers new data on the distinctive...geographers had referred—in the interior of what is now Zimbabwe, near Hartley (now Chegutu). Subsequently, after |  | | Report (issue) | | ar·tificial st.aining . In a r·estricted sense the term chalcedony a,pplies only to those varieties of uniform pale...these stonesJ is built up of narrow layers of chalcedony of differen,t transparency or colour, often airranged...£01~ heliodor. Porous stones such as a.gate and chalcedony are very fre•q uently dyed to represe11t onyx...deposits of rich •d iamantiferous grav.els in th,e district around Akwatia, which is 5 miles S.E. of· Kade...Foting·aia., 6½ miles N.N.W. of Jajma in the Kono district, a11d there was a find near Kennema in 1931. The |  | | Journal (article/letter/editorial) | | C., 1,72o S.), as well as secondarysilicaand chalcedony. The decompositionand alteration seem to have...serpentine, calcite,chlorite, spinelzeolitesand chalcedony. The rock was found in nearly every case to be...contradictionof the above theory in the Pretoria district of the Transvaal, where Dr. G. A. Molen- graaf...19o3, 236-238; LXXIX, 19o5, 128-129. The Diamond District of the Vaal River. Eng. Mng..[our., LXXVI., 19o3...Chicago, •9o3. Gemsand Gem t'le•, $. 8. The Somabula DiamondField. Geol.Mag. (5), III., .i9o6. 569-57øß |  | | Book (edition) | | extensive fields in the prophetically named Kimberley district of Western Australia promise to be of world importance...Smith gave valuable information on the new chrome chalcedony found in Rhodesia. The staff of both western...have been cut as gems are those from Sandawana in Zimbabwe, where the pegmatite veins containing the emeralds...Figure 1.26 Emerald in pegmatite from Sandawana, Zimbabwe 30 The Ages of Gems About 2565 million years...Colombia and the Archaean (2600 Ma) deposits in Zimbabwe, emeralds have formed at many different times |  | | Book (edition) | | Amethyst, Cairngorm, Cats-Eye, Tiger's-Eye) XXIX. Chalcedony, Agate, Etc . 228 Cymo- Cats-Eye, 233 Citrine...orientation, as in the case of conjunction chalcedony and individuals to agate. become So by...typical French family pere, mere, et in the Jura district, all busily engaged; on fils — the table will...diamonds were bought and sold. The diamond-bearing district actually spread over a wide area on the eastern...km.) from Rio de Janeiro, in the Serro do Frio district of the State of Minas Geraes. The discovery naturally | | | Book (edition) | | Tigers-Eye) . 228 Cymo- Cats-Eye, Amethyst, XXIX. CHALCEDONY, AGATE, ETC. 207 Topazolite, . (Rubellite)...any definite orientation, as in the case of chalcedony and agate. So by supposing the become infinitesimally...typical French family pere, mere, et in the Jura district, all busily engaged on the table will be noticed...diamonds were bought and sold. The diamond-bearing district actually spread over a wide area on the eastern...km.) from Rio de Janeiro, in the Serro do Frio district of in stones were The discovery naturally caused |  | | Thesis/Dissertation | | and4). -4- alluvial diggings in the Bark1y West District was 19 745 carats (Axse1,1988). 2. THE DIFFERENT...2 VENTERSDORP SUPERGROUP In the Barkly West District, the Ventersdurp Supergroup is only represented...the coarse-pebble grade. These gravels contain chalcedony, agate, quartz, and quartzite with a surface...present flood level. Gravel compos it ion Quartz, chalcedony, chert, agate, jasper, quartzite, slliclfied...ventersdor~ andesite with minor sha e, dolerite, quartz chalcedony, agate, Jasper, chert, quartzite, banded ironstone |  | | Journal (article/letter/editorial) | | Unst, Shetland, '54, 399 Amisk-Athapapuskow Lake District, '20, (R) 282 Ammonite, new Name for Lias, D....Hemisphere, '39, 489 Jurassic Iron Ores, Cleveland District, '42, (R) 207 ; Chloride Waters of Great Britain...Perthshire, Unusual, W. T. Harry, '52, 41 Appleby District, Geology of, '15, (R) 431 ; '42,(R)78; '52, (R)...70 Assynt Culmination, E. B. Bailey, '35, 151 — District, Geological Excursion Guide, '38, (R) 140 — Mountains... Geological, Photographic, '13, (R) 424 Atlin District, British Columbia, '14, (R) 129 Atmospheric Erosion |  | | Book (volume) | | gem and lithiumbearing pegmatites of the Pala district of San Diego County, California, from which much...the most important being those of the southern district. Although so important in the past they are now...(By courtesy of Sothebys) In the Bundelkhand district of Central Provinces, between the rivers Ken and...Central Provinces and in the neighbouring Sambalpur district of Orissa. These mines have, in general, been...Sanggau on the Kapuas river. Another diamondiferous district lies in the south-east of the island in the area |  | | Book (edition) | | ( Chrysolite, . Topazolite , . . . . Chalcedony, Agate, . 225 . . Cats-Eye, 228 Cymo- ...composed composite conjunction without and chalcedony twinning minute as to a It to and for...et a more at a — , fils — in the Jura district, the table will be kind noticed described above...actually spread side Pinner in the bought were district eastern the known from Golconda India. ...was gold (129 km.) development of the diamond district Brazil rendered it Brazil, Small the discovery |  | | Book (edition) | | 228 Cymo- Cafs-Eye, . (Rock- Crystal, XXIX. CHALCEDONY, AGATE, ETC. . .216 .218 ., (Jargoon, Hyacinth...any definite orientation, as in the case of chalcedony and agate. So by supposing the become infinitesimally...typical French family pere> mere, et in the Jura district, all busily engaged on fils the table will be...diamonds were bought and sold. The diamond-bearing district actually spread over a wide area on the eastern...km.) from Rio de Janeiro, in the Serro do Frio district of The discovery naturally caused great excitement |  | | Book (edition) | | Ceylon. Rhodesia, and S.W. Africa: Sri Lanka, Zimbabwe, and Namibia, respectively. However, although...2 USSR USSR 51 -38.8 Asbestos, 44 14.4 Zimbabwe Colombia Illinois 3.3 -20.2 14.8 7 3 18.4... Michigan. Domeykite Superior is from the district, Mohawk Mine, Michigan; Lake Ontario, Canada;...Tintic, Utah; Arizona; New Mexico; Coeur d'Alene district, Idaho. Hill, = 1 Anglesite gems are colorless...Cut Cut Color Ocean Kenya dark green 1.641 Zimbabwe yellow-green yellow Burma dark green green |  | | Journal (article/letter/editorial) | | eluvial in the Rondonia tinwith beveled mining district, Brazil.detrital topaz from eluvial placer deposits...Rondonia tin mining edges, Brazil. (c) Anhedral district, Brazil. Two processes, tectonic uplift and unroofing...gravel beds in the upper Karoo are operated at Somabula, Zimbabwe, not only for diamonds, but also for topaz...the row is the multicolored agate, a variety of chalcedony (fine-grained quartz). (Figure 16a). Especially...deposits (1) Silcretes (1) Quartz (40a H) (2) Chalcedony (40c H) (3) Opal (40d H) (2) Rock crystal placers |  | | Book | | mica and chlorapatite. The Sandawana emeralds of Zimbabwe show tremolite crystals which are more hair-like...quartz such as the jaspers are distinct from the chalcedony group, the members of which tend to be fibrous...appear green to greyish-green. Stained green chalcedony, showing pink when chromium is added, can be...and in the blue at 455 nm. 11. CHROME-BEARING CHALCEDONY (MTOROLITE) has a strong clear doublet in the...the deep red but not much else. Stained green chalcedony shows an indistinct band in the red at the doublet | | | Book | | mica and chlorapatite. The Sandawana emeralds of Zimbabwe show tremolite crystals which are more hair-like...quartz such as the jaspers are distinct from the chalcedony group, the members of which tend to be fibrous...appear green to greyish-green. Stained green chalcedony, showing pink when chromium is added, can be...and in the blue at 455 nm. 11. CHROME-BEARING CHALCEDONY (MTOROLITE) has a strong clear doublet in the...the deep red but not much else. Stained green chalcedony shows an indistinct band in the red at the doublet |  | | Book (edition) | | Citn"ne, Caimgor1111 Cat's-Eye, Tiger's-Eye) XXIX. CHALCEDONY, AGATE, ETC. 233 238 246 CONTENTS xi CIIAr...without any definite orientation, as in the case of chalcedony and agate. So by supposing the individuals to...French family--pere, mere, et .fi/s-in the Jura district, all busily engaged; on the table will be noticed...diamonds were bought and sold. The diamond-bearing district actually spread over a wide area on the eastern...km.) from Rio de Janeiro, in the Serro do Frio district of the State of Minas Geraes. The discovery naturally |  | | Book (edition) | | and the remainder are included in Section C. Chalcedony, turquoise, and jade have been transferred to...XXXYV. 307 FAMILY 397 C—ORNAMENTAL STONES CHALCEDONY 401 GREENISH 405 STONES 414 XL. JADE XLI...to crystallization, it is often transformed to chalcedony. CRYSTAL FORM (B) CRYSTAL AND STRUCTURE...when dealing with porous material like agate and chalcedony, since any kind of foreign matter may be absorbed...sophisticated eyes. The art of staining agate and chalcedony is no new discovery, and the possibility was |  | | Book (edition) | | bloodstone ” (but distinct from the variety of chalcedony now kpown as bloodstone). The green colour of.... . * * . * Komerapine Idocrase Olivine Chalcedony Epidote .. Spbene Hypersthene Rhedonite Cordierite...Fibrolite Rhodonite 6 Turquoise Haematite Chalcedony 6 Euclase Zircon Beryl Phenakite Opal . ...is now done on carborundum wheels. In the Idar district in Germany agate and other quartz varieties are...ground, which extends to an bedded rocks of the district. in the upper part of the pipes, it In the early |  | | Journal (article/letter/editorial) | | Ceriopyrochlore Cerite Cerussite Chabazite-(Ca) Chalcedony Chalcocite Chalcomenite Chalcophanite Chalcopyrite...Zr)(Si2O7)2OF3 Hg2I2 Ag2Hg3 Pb (Zn,Cu)(OH)(VO4) chrom chalcedony Na3Ti3.6 Nb0.4(Si2O7)2O4·4(H2O) KAl2(Si3Al)O10(OH...Chromium deposits of this type in South Africa and Zimbabwe contribute to more than 90% to the world supply...subtypes (Bushveld, South Africa, Great Dyke, Zimbabwe, Muskox, Canada, Dore Lake, Australia, Campo Formoso...South Africa (Fe, Cr, and PGE) and the Great Dyke, Zimbabwe (Cr, PGE/PGM) in idealized cross sections and |
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