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| Microstructure and origin of colour of chrysoprase from Haneti (Tanzania) Heribert A. Graetsch With 4 figures...figures and 1 table Abstract: Chrysoprase from Haneti, Tanzania, was investigated by optical reflectance...spectroscopy and X-ray powder diffraction. Different to chrysoprase from other sources, the green colour is caused...varieties of chalcedony, the microstructure of chrysoprase is characterised by planar lattice faults, a...crystallinity of chrysoprase from Haneti is higher than from many other sources. Key words: chrysoprase, gaspeite |
 | | Book |
| gemological wealth of East Africa. This unique region encompasses ·what may be the world's richest gem...gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical splendor...greener-than-emerald tsavorite. Unique geochemistry in the area holds out the possi~ility of additional new finds...chrome tourmaline are widely identified with the region. ( continuedon backflap) ♦ ♦ ♦ ♦ ♦ ~...Conclusion 11 Chapter 2. Diamond Deposits of Tanzania 15 Location 16 Geology 18 Mining 20 Properties |
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| Review Nanocut Plasma-Etched Diamonds Chrysoprase from Tanzania Demantoid from Italy THE QUARTERLY JOURNAL...___________ pg. 267 271 Chrysoprase and Prase Opal from Haneti, Central Tanzania James E. Shigley, Brendan...and gemological characteristics of Tanzanian chrysoprase and green prase opal are revealed. 280 Demantoid...the Kagem mine, Zambia • Yellow grossular from Tanzania • An unusual blister pearl • Myanmar report •...Kashmir (in what is now the Indian part of the region) in 1881 after a landslide revealed the blue gems |
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| for his study of igneous rocks in the Balmoral area, Aberdeenshire. He joined the staff of the British...the importance that the tribes of the tidal water region placed upon pearls for adornment. Some thirty tribes...Kalahari Manganese Field (Figure 1). That That region is well known for occurrences of of gem sugilite...OLIFANTSHOEK • 1. Geographical map of the Kuruman region in the Kalahari Manganese Field with the Black...Mediterranean is an enviable one. It is situated in a region of great natural beauty. Its success as host to |
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| 'plume' structure (Figure 2). One small, irregular area has a dark yellowish brown colour with wavy, agate-like...animal, vegetable, and mineral products of the region, all of ISSN: 0022-1252 464 which were exchanged...result of a several weeks stay at Matara, which gem district he visited in response to an urgent request for...J. Gemm., 1991,22,8 especially from the Matara area, which have been heat-treated to drive off colour...Belligam. He also noted that zircons of the Matara district receive the name "Matara diamonds" for their finest |
 | | Journal (issue) |
| 316 Gem News International Chondrodite from Tanzania • Blue dolomite from Colombia • Fluorite from...is still the natural beige color. Digging into an area of dark purplish gray matrix with a needle probe...function of surface area. As scratches represent localized zones of high surface area, it is reasonable...The dye penetrated the stone much deeper in the area immediately surrounding the scratched letters (figure...faster in localized regions with a high surface area, such as pits and scratches (left and center). After |
 | | Catalog/List |
| Signature® Internet Session 2 Heritage Auctions Design District Annex 1518 Slocum Street • Dallas, TX 75207 (HERITAGELive...the Tsumeb Mine (as well as other mines of the region) were still in production in the 1970s. You will...mines on the remote and desert-like "Sperrgebiet" area of the southern coast of Namibia, with its fabulous...Azurite Level 8, Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia If the attachment point on the back of...Topaz Klein Spitzkopje, Spitzkopje Area, Karibib District, Erongo Region, Namibia Klein Spitzkopje in Afrikaans |
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| brealzdown of dolomite, for CO,] within the peridotite area of stability in the mantle, resulting in the selfdestruction...13. Inspection of this figure will show a shaded area in the narrow range of - 2 to - 9 813C, with a peak...peak between - 5 and - 6 613C. This is the area in which almost all peridotitic diamonds will plot. Although...peridotitic rock origins is illustrated here. The shaded region, wilh 613C val~resof - 2 to -9, is the ronge for...plate being moved downward (subduction) into a region of higher pressures and temperatures below a craton |
 | | Journal (issue) |
| for this study were purchased at two Los Angeles-area lapidary supply shops (figure 2). A number of dealers...breaking table surface appears iridescent in one area No additional change No additional change No additional...Emeralds are again being mined in the historic district of the Ural Mountains. Physical, chemical, spectroscopic...resulted from the limited mining that continued in the region. Today, though, there appear to be large quantities...Malysheva, situated in the old Talzovaya River mining area. Apparently, the Malysheva mine has been exploited |
Haneti-Itiso area, Chamwino District, Dodoma Region, Tanzania