 | | Book | | GEMSTONES of East Africa Burundi, Kenya, Rwanda, Tanzania and Uganda Bruce Cairncross Published by Struik...resources 12 Burundi 13 Kenya 14 Rwanda 16 Tanzania 17 Uganda 20 Gemological properties 21 A to...through Tanzania, Kenya, Ethiopia and into the Sudan - has blessed East Africa, Kenya and Tanzania, with...starting in what was then Tanganyika ( now mainland Tanzania) and then progressing to Kenya - I am proud to...countries are among the finest in the world. The region and its gems are particularly dear to my family |  | | 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...Azurite Level 8, Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia If the attachment point on the back of...Klein Spitzkopje, Spitzkopje Area, Karibib District, Erongo Region, Namibia Klein Spitzkopje in Afrikaans...Pseudomorph after Azurite Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia Some of the best things to come from the |  | | Journal (issue) | | 28 ct blue spinel, (6) 1.17 ct benitoite, (7) 2.14 ct blue sapphire, (8) 23.18 ct blue spinel, (9) 4.82...8.04 ct orange sapphire, and (18) 3.48 ct pink spinel. The necklace contains 25.85 ct of radiant-cut...Asia (Myanmar, Thailand, and Vietnam), Africa (Tanzania, Kenya, Zimbabwe, Nigeria, and Namibia, as well...a wide variety of colored stones from southern Tanzania; spessartine garnet from Nigeria and Namibia;...northern Canada for the first time. Names such as Tunduru, Ilakaka, and Ekati were unknown to the gem trade |  | Giuliani, Gaston, Fallick, Anthony E., Feneyrol, Julien, Ohnenstetter, Daniel, Pardieu, Vincent, Saul, Mark (2011) 18O/16O and V/Cr ratios in gem tsavorites from the Neoproterozoic Mozambique metamorphic belt: a clue towards their origins?. Mineralium Deposita, 46 (7) 671-676 doi:10.1007/s00126-011-0355-6 | Journal (article/letter/editorial) | | main productive areas from northern and southern Tanzania, Kenya, and Madagascar. Three consistent sets...Saul Swala Gem Traders, Sokoine Road, Arusha, Tanzania deposits hosted in graphitic gneisses related...discovered by Bridges in 1967, in northeastern Tanzania, is among the most successful recent gemstones...significant tsavorite deposits are found in Kenya, Tanzania, and Madagascar. The geology of the deposits has...partly in the Voi region in Kenya (Pohl and Niedermayr 1978) and Merelani mines in Tanzania (Malisa 1987; |  | | Journal (issue) | | emerald mine is part of Colombia’s Muzo mining region, an 800 km2 area that encompasses the famous Muzo...emerald district in Colombia, and it is the most productive and well-known emerald mining region in the...historic mine to other famous producers in the region. Keywords: Colombia, emerald, geology, inclusions...Peñas Blancas, located in the famous Muzo mining district. This mine has rarely been mentioned in gemmological...is somewhat different from the three other Muzo-region mines, the fine quality of the emeralds (e.g., |  | Giuliani, Gaston, Fallick, Anthony, Rakotondrazafy, Michel, Ohnenstetter, Daniel, Andriamamonjy, Alfred, Ralantoarison, Théogène, Rakotosamizanany, Saholy, Razanatseheno, Marie, Offant, Yohann, Garnier, Virginie, Dunaigre, Christian, Schwarz, Dietmar, Mercier, Alain, Ratrimo, Voahangy, Ralison, Bruno (2007) Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin. Mineralium Deposita, 42 (3) 251-270 doi:10.1007/s00126-006-0105-3 | Journal (article/letter/editorial) | | placer deposits from Sri Lanka, Madagascar, and Tanzania have a large variety of colored sapphires and...deposits linked to basaltic rocks in the northern region (Schwarz et al. 2000). Most of the economic ruby...consist of plagioclasite veins or segregations with ± spinel, ± corundum, ± hibonite, and ± phlogopite. Placer...Ambondromifehy area and on Nosy Be Island (Fig. 1). The region is mostly covered by a 3,500-km2 area of volcanic...presence of a crystal of sapphire, zircon, and spinel associated with hornblende and syenitic enclaves |  | | Journal (issue) | | South Korea Kamal Kothari, India Bhadresh Pandit, Tanzania Clement Sabbagh, Brazil Capt. Ramji Sharma, Japan...of the to the UAE, during the Dubai show where region. To aid ICA exhibitors, worldwide financial crisis...computer equipment at the schools in the Tourmalina district of Minas Gerais. The ICA contribution is part...and brighter compared with those from the Tsavo region. While a problem in small stones where it results...potential. Tsavorite is commercially mined in Tanzania, Kenya and Madagascar, mainly from deposits located |  | | Journal (issue) | | alluvial sapphires from Russia’s Jewish Autonomous District. 266 A New Deposit of Gem-Quality Grandidierite...Mobile fluorite inclusion in quartz • Inclusions in spinel from Madagascar • Sphalerite in topaz • Tourmaline...in Mexico • Colored gemstone mining update from Tanzania • Purple pyrope-almandine garnet from Mozambique...corundum-bearing rocks at Sutara, in the Jewish Autonomous Region of the Russian Far East. The authors postulate...741.2 nm and related absorption in the visible region; the latter imparts a green to blue color. An interesting |  | D’Ippolito, Veronica, Andreozzi, Giovanni Battista, Hålenius, Ulf, Skogby, Henrik, Hametner, Kathrin, Günther, Detlef (2015) Color mechanisms in spinel: cobalt and iron interplay for the blue color. Physics and Chemistry of Minerals, 42 (6) 431-439 doi:10.1007/s00269-015-0734-0 | Journal (article/letter/editorial) | | 1007/s00269-015-0734-0 ORIGINAL PAPER Color mechanisms in spinel: cobalt and iron interplay for the blue color Veronica...Heidelberg 2015 Abstract Six natural, blue colored spinel crystals were studied chemically by electron microprobe...principal composition of the samples (gahnite vs. spinel s.s.). Although blue colors in spinels are frequently...MFe2+, MFe3+ and Fe2+–Fe3+ cation pairs. Keywords Spinel · Cobalt · Blue color · LA-ICP-MS · UV–VIS–NIR–MIR...belonging to the spinel group are actively sought as gemstones, while synthetic spinel powders are widely |  | | Journal (issue) | | .......................................... 47 Tanzania.................................................Takada, Japan Dong Keuk Kim, Korea Bhadresh Pandit, Tanzania Janet Ann Russell, Thailand Surasit Sriorathaikul...Ambassador, Pakistan; Eric Saul, ICA Ambassador, Tanzania; Thomas R. Yager; Dr. Dietmar Schwarz, Switzerland;...most of the production is mixed with calcite. The spinel mine at Kuh-i-Lal is being operated by a skeleton...minister of mineral resources who said he believed the region needed new areas to prospect, as there have been |  | | Journal (issue) | | of Aurora Gems; (6) a 9.15 ct ruby from Winza, Tanzania, courtesy of Hakimi & Sons; (7) a 14.80 ct “golden”...were combined under the jurisdiction of the U.S. District Court of New Jersey 168 PRODUCTION AND MARKETS...Africa, and its interest in the Williamson mine of Tanzania. Soon after the Cullinan deal went though (July...Weldon, 2009). One new source of corundum, Winza in Tanzania, began yielding some fine-quality ruby in 2007...with the opening of a new mine in the Nova Era region and technological developments at established mines |  | Andreozzi, Giovanni B., D’Ippolito, Veronica, Skogby, Henrik, Hålenius, Ulf, Bosi, Ferdinando (2019) Color mechanisms in spinel: a multi-analytical investigation of natural crystals with a wide range of coloration. Physics and Chemistry of Minerals, 46 (4) 343-360 doi:10.1007/s00269-018-1007-5 | Journal (article/letter/editorial) | | 1007/s00269-018-1007-5 ORIGINAL PAPER Color mechanisms in spinel: a multi-analytical investigation of natural crystals...natural spinel single crystals displaying colors almost representative for the entire spinel variability...revealing that the color displayed by aluminate spinel crystals is due to a combination of two or more...coordinated sites of the spinel structure. Iron-poor orange, red and magenta spinel crystals owe their color...for red color). Iron-rich pink, blue and green spinel crystals, in spite of exhibiting very different |  | | Journal (issue) | | Inspection) DNA fingerprinting of pearls Blue cobalt spinel from Vietnam Ethiopian opal stability experiment...at Pyaung-pyin, where both large- sapphire and spinel is found. The miners collect strongly decomposed...at the morning Mogok market. Ruby, sapphire and spinel are commonly sold at the market. © Laurent E. Cartier...13 · facette 2014 ssef research Blue cobalt spinel from Vietnam W e would like to congratulate Ms...combination completion of her bachelor thesis on cobalt-spinel from with their distinct iron concentration of |  | | Journal (issue) | | since over 25 years abroad, mainly in Thailand, Tanzania, Kenya and Madagascar. He speaks besides German...the trip from Nairobi and visited Madagascar and Tanzania within three weeks. It was surprising to see how...Chanthaburi as in Tananarivo or in Mombasa or Arusha. Tanzania Werner Spaltenstein sat in the office of his agent...(peristerite), kornerupine, clinohumite, diopside or large spinel crystals. Werner priced the merchandise quickly...plane Fig.2 River landscape at the Muhuwesi near Tunduru (STanzania) containing gem minerals in its gravels |  | Giuliani, Gaston, Groat, Lee, Fallick, Anthony, Pignatelli, Isabella, Pardieu, Vincent (2020) Ruby Deposits: A Review and Geological Classification. Minerals, 10 (7) 597 doi:10.3390/min10070597 | Journal (article/letter/editorial) | | for gems mined from the modern-day Tajikistan (spinel), and “Bohemian ruby” was used for gems coming... with a hardness of 9 on the Mohs scale (while spinel and garnets crystallize in the cubic system and...and are softer with a hardness of 8). Unlike spinel and garnet, ruby is a dichroic mineral, which will...Vatomandry; (2) Andriba; (Antsirabe-Antanifotsy region, Soamiakatra-Ambohimandroso; Ambohibary); (3) Zazafotsy;...Zazafotsy; Ankaratra (Antsirabe-Antanifotsy region, Soamiakatra-Ambohimandroso; Ambohibary); (3)IlakakaZazafotsy; |  | | Journal (article/letter/editorial) | | anthophyllite ± green pargasite ± green or red spinel ± sapphirine ± cordierite (up to 30 cm single crystals)...precursor (Polat et al. 2009). The greater Fiskenæsset region was meta; 50°W Grædefjord ; den æsfjor ;...Maniitsoq Storø Kapisillit Nattivit Winza Umba Tunduru Sahabano Zazafotsy 60 Qaqqatsiaq Aappaluttoq...Chanthaburi in Thailand, Pailin in Cambodia and Winza in Tanzania. Rubies from all these localities are hosted by...granulite-facies relations in the Fiskenæsesset region, southern West Greenland. The Journal of Geology |  | | Journal (issue) | | Summer 2019 Issue 43 All About Colored Gemstones Spinel In All Shades & Sparkling Colors A Publication...Jewelry Industry Special Spinel Pink and Red Gem Spinels in Marble and Placers Spinel from Tajikistan – The...The Spinels of Mahenge, Tanzania In Search of Cobalt Blue Spinel in Vietnam Spinel Inclusions – An Exercise...Exercise in Aesthetics Spinel – A Gemstone for Kings 66 InColor InColor is the official publication of...10 4 InColor Summer 2019 A 7.13-ct spinel from Mahenge, Tanzania. Cover image: Prangpak Ruahong, Nomads |  | | Journal (issue) | | vivid “canary” yellow elbaite from the Lundazi District of eastern Zambia, the most important source of...Namibia • Andradite from Pakistan • Axinite from Tanzania • Baddeleyite from Mogok, Myanmar • Chrysocolla...and chondrodite from Tanzania • Transparent dumortierite and sapphirine from Tanzania • Brazilian blue “opal”...am, out in the middle of the Tanzanian bush at Tunduru, spitting distance from Mozambique, on the Muhuwesi...the CVD synthetic diamonds. In the mid-infrared region, samples in the near-colorless group showed no |  | | Journal (issue) | | is a dominant lithology within the Okkampitiya region. The marble is composed mainly of calcite and dolomite...diopside, phlogopite, and accessory spinel and apatite. The spinel shows a well-developed octahedral habit...yellow and colourless), garnets including hessonite, spinel, tourmaline and zircon, in order of decreasing... J. Gemm., 2000, 27, 2, 65-72 slopes, where spinel and tourmaline are more prominent. The corundums...Bibile region. In contrast to the effects of strong mechanical abrasion shown by corundum, spinel and tourmaline |  | | Journal (issue) | | to those found in the Umba valley and Tunduru area in Tanzania whereas the blue sapphires are reminiscent...similar to the alluvial deposits of Sri Lanka and Tanzania and the three areas may have been part of single...of the discovery spread, people from the whole region rushed to the area seeking their fortune in gemstones...been concentrated in three main areas. The first region includes a 90 x 20 km wide belt between Ranohira...the colours of sapphires found in Tanzania (Umba valley and Tunduru). Madagascar has however yielded pink |  | | Journal (issue) | | of African origin, most probably all from Tunduru, Tanzania, are presented. The faceted gemstones were...and recently, several samples from the Tunduru area in Tanzania have been described (anonymous, 1996;...and quantitative chemical data of material from Tanzania are unknown. Due to the similar chemical composition...Schmetzer, 1998). Because all specimens from Tunduru have so far been determined only by traditional...is not known whether the samples described from Tanzania as taaffeites (anonymous, 1996; Burford, 1998) |  | | Journal (issue) | | Index ABOUT THE COVER: The historic Ouro Preto region of Minas Gerais, Brazil, is world-renown for the...Capiio mine is one of the most productive in the region. This mine and the superb topazes produced there...Today, the region lznown i n the world gem market as the Ouro Preto Imperial topaz district comprises...operation is the Cap50 mine, in the Rodrigo Silva district. Specimens and information about that mine were... Figure 1. The fine Imperial topazes from the region near Ouro Preto, in Minas Gerais, Brazil, are most |  | | Journal (issue) | | kilobars and temperatures of 1400°C –1700°C. In this region of the diamond stability field (see figure 2),...color-change garnets have been known from Sri Lanka and Tanzania, interest in this phenomenal material has grown...rapidly with the discovery of new deposits near Tunduru (Tanzania) and especially Madagascar. In particular...and Athiliwewa, in Sri Lanka; or Umba and Tunduru, in Tanzania (see references given above as well as Koivula...range, respectively. absorption band in the yellow region, an absorption minimum always is found in the blue-green |  | | Journal (issue) | | exceptional 4.10 ct concavefacet ruby from Winza, Tanzania, courtesy of Mark Gronlund. Photo by Robert Weldon/GIA...Kenya (612 ± 6 Ma; Simonet, 2000), Longido in Tanzania (610 ± 6 Ma; Le Goff et al., 2010), and the Vohibory...Morogoro (MM), Kalalani and Umba (K), Songea (S), Tunduru (T). Mozambique: Montepuez (Mz); Madagascar: Ilakaka...and Sahambano (ZS), deposits from the Vohibory region (Vo), Ambatomena (Am), Andranondambo (An), Andilamena...sapphires from the Ambondromifehy placers, Antsiranana region, Madagascar; photo by G. Giuliani. B: Sapphire |  | | Journal (issue) | | 322 Rubies and Sapphires from Winza, Central Tanzania Dietmar Schwarz, Vincent Pardieu, John M. Saul...“D-TO-Z” DIAMONDS diamonds from the Cape of Good Hope region, and “Jager” for colorless diamonds with strong...of color in a diamond. In the New York jewelry district on Maiden Lane, neighboring buildings were painted...the blue region of the spectrum, as it is the absorption area of wavelengths in this region that allows...the 6-watt lamps used in the past. Here, the UV region shows good agreement between the three lamps. Note |
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