| 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 |
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(2019, Summer) InColor 43. International Colored Gemstones Association |
Journal (issue) |
| Spinels from Sri Lanka 54 The Spinels of Mahenge, Tanzania In Search of Cobalt Blue Spinel in Vietnam...InColor Summer 2019 A 7.13-ct spinel from Mahenge, Tanzania. Cover image: Prangpak Ruahong, Nomads. 40...million and China's Hong Kong Special Administrative Region (SAR) with US$30.8 million, said the ministry's...ancient Kingdom of Balascia, related to Badakhshan, a region spanning parts of present-day Afghanistan and Tajikistan...are found in Tajikistan, Myanmar, Vietnam and Tanzania (Yavorskyy and Hughes, 2010; Giuliani et al., |
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Moore, Thomas P. (2019, April 13th) What's New in the Mineral World? 52. The Mineralogical Record, Inc. |
Report (issue) |
| Manyara Region, Tanzania; brilliant red spinel octahedrons from Mahenge, Morogoro Region, Tanzania; and...octahedral crystals, from a “new find” at Ruaha, near Mahenge. These newer spinels look very fine and are unusual...$750. Spinel, 4.8 cm, from Ruaha, Manyara Region, Tanzania. Marin Mineral Company specimen and photo... 3.2 cm, from the Merelani mines, Manyara Region, Tanzania. Marin Mineral Company specimen and photo... Khyber Mineral Company specimen and photo. Forsterite variety peridot, largest crystal 1.5 cm, from |
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Wu, Jinlin, Sun, Xueying, Ma, Hong, Ning, Peiying, Tang, Na, Ding, Ting, Li, Huihuang, Zhang, Tianyang, Ma, Ying (2023) Purple-Violet Gem Spinel from Tanzania and Myanmar: Inclusion, Spectroscopy, Chemistry, and Color. Minerals, 13 (2) 226 doi:10.3390/min13020226 |
Journal (article/letter/editorial) |
| minerals Article Purple-Violet Gem Spinel from Tanzania and Myanmar: Inclusion, Spectroscopy, Chemistry...com.cn Abstract: Purple-violet gem spinels from Tanzania and Myanmar have been investigated for their gemological...inclusions, including dolomite, phlogopite, and forsterite in Tanzanian spinel and magnesite, apatite, baddeleyite...hue angle and lightless of purple spinels from Tanzania. However, due to the relatively stable content...study are of a limited number of samples from Tanzania and Myanmar. Citation: Wu, J.; Sun, X.; Ma, H |
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Giuliani, Gaston, Fallick, Anthony E., Boyce, Adrian J., Pardieu, Vincent, Pham, Van Long (2017) Pink and Red Spinels In Marble: Trace Elements, Oxygen Isotopes, and Sources. The Canadian Mineralogist, 55 (4) 743-761 doi:10.3749/canmin.1700009 |
Journal (article/letter/editorial) |
| from Paigutan in Nepal, Kiswila and Ipanko in Tanzania, Pamreso in Kenya, Mogok in Myanmar, and An Phu...Yen area, Vietnam. (E) Spinel (Spl) in forsterite (forsterite, Fo þ lizardite, Lz) skarn rock associated...in Tajikistan, Myanmar, Vietnam (Fig. 1A), and Tanzania (Yavorskyy & Hughes 2010). Occurrences are known...paragenesis consists of calcite, dolomite, spinel, forsterite, clinohumite, apatite, margarite, pargasite,...associated with mostly calcite (Cal) - dolomite (Dol), forsterite (Fo), clinohumite (Chu), pargasite, phlogopite |
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Keller, Peter C (1992) Gemstones of East Africa. Geoscience Press, Inc. |
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...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...Northern Province, Tanzania 28 Ruby and Sapphire from Umba, Tanga Province, Tanzania 32 Sapphire from Kenya |
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Sutherland, Frederick Lin, Zaw, Khin (2020) Mineralogy and Geochemistry of Ruby. MDPI. doi:10.3390/books978-3-03943-616-3 |
Book |
| the Australasian region. He works closely with his counterparts from the SE Asia region. He leads industry-CODES-funded...deposits from Montepeluez, Mozambique; Winza, Tanzania; Andilamena/Zahmena and Ampanihy/Toliara, Madagascar...Luc Yen, Vietnam; Jegdalek, Afghanistan; Morogoro, Tanzania. Metamorphic blue sapphire deposits included...triangular figure, it separated fields from Winza, Tanzania, Namehaca, Mozambique and Ampanihy and Zahmena...and Fe vs. V could roughly divide Myanmar and Morogoro area rubies, while ternary diagrams for Fe/Mg |
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(2020) The Journal of Gemmology Vol. 37 (4) Gem-A |
Journal (issue) |
| west of Sakoany village in the Mahajanga (Majunga) region on the north-western coast of Madagascar, near...(605 nm) was somewhat shifted towards the blue region and it lacked Figure 1: This 4.22 ct celestine...inclusions in the ruby permitted the features in this region to be fully resolved. Corundum is anhydrous and...Because vesuvianite absorbs strongly in the mid-IR region of the spectrum, even minute inclusions can give...vesuvianite showed total absorption corresponded to the region of the compound band structure in the 2.19 ct ruby |
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(2008, January) Gems & Gemology Vol. 44 (4) Gemological Institute of America |
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...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...that results in an additional emission in the red region between 620 and 700 nm that does not have a noticeable |
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(2000, January) Gems & Gemology Vol. 36 (4) Gemological Institute of America |
Journal (issue) |
| 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;...the country rather than to the specific mine or region. For more on the specific localities, consult tables...mines have prompted active exploration in this region (Schwarz, 1999). Emerald mining also continued...as alexandrite—has been the Tunduru region of southern Tanzania, which has produced an amazing variety |
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Keulen, Nynke, Thomsen, Tonny B., Schumacher, John C., Poulsen, Majken D., Kalvig, Per, Vennemann, Torsten, Salimi, Rita (2020) Formation, origin and geographic typing of corundum (ruby and pink sapphire) from the Fiskenæsset complex, Greenland. Lithos, 366. 105536pp. doi:10.1016/j.lithos.2020.105536 |
Journal (article/letter/editorial) |
| Ruby in Kangerdlussuaq (Maniitsoq region) and on Storø (Nuuk region) formed by a metamorphic reaction...Seza Kofi and Longido (mainly ultramafic setting, Tanzania) and with the basaltic samples from Cambodia and...samples from Kapisilit and Storø (both in the Nuuk region) also yield δ18O values that lie within the mafic-ultramafic...in leucogabbro or anorthosite and serpentinite/forsterite in an ultramafic rock, triggered by the intrusion...pressure decrease would move the rocks into the P-T region for Plg-Crd-Spr-Oam (Figure 11), where cordierite |
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(2015, Spring) Gems & Gemology Vol. 51 (1) Gemological Institute of America |
Journal (issue) |
| sequence. B lue spinels are mined in Sri Lanka, Tanzania, Myanmar, Pakistan, and Vietnam (Shigley and Stockton...rich in forsterite (magnesian olivine). The gem is often associated with calcite, forsterite, pargasite...blue spinel is always associated with olivine (forsterite) and pargasite in calcite matrix. Clinochlore...examined with EDS analysis. Olivine is 99% pure forsterite (Mg2SiO4). Pargasite is rich in titanium, sodium...spectra, in the violet to blue region (400– 500 nm) and in the red region (670–700 nm). We also observed |
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(2016, Fall/Autumn) Gems & Gemology Vol. 52 (3) Gemological Institute of America |
Journal (issue) |
| 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...with absorption, which extends into the visible region and becomes less intense at shorter wavelengths...discovered at Sutara, in the Jewish Autonomous Region of the Russian Far East. These sapphires are typically |
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(2022) The Journal of Gemmology Vol. 38 (6) Gem-A |
Journal (issue) |
| China More on Emeralds from Chitral, Pakistan _Forsterite_-Serpentine from North-eastern China Portraits...Central Madagascar | Spessartine from Engare Naibor, Tanzania |
Update on Colourless HPHT-grown Synthetic Diamonds...emerald deposit was discovered in 2021 in the Chitral region of north-western Pakistan. Following an earlier...and Gemmological Characteristics of Gemquality _Forsterite_-Serpentine from North-eastern China 600 By...616 By Erik Schoonhoven 621 Conferences 546 _Forsterite_-Serpe ntine from North -eastern China / No. |
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Alemayehu, Melesse, Guo, Feng, Aulbach, Sonja (2019) Transformation of continental lithospheric mantle beneath the East African Rift: constraints from platinum-group elements and Re–Os isotopes in mantle xenoliths from Ethiopia. Contributions to Mineralogy and Petrology, 174 (5) doi:10.1007/s00410-019-1577-3 |
Journal (article/letter/editorial) |
| events in Page 3 of 27 40 the SCLM beneath the region, are well documented from Mega xenoliths (Lorand...less volcanic Western branch that adjoins the Tanzania craton and an older, volcanically active Eastern...reported in Alemayehu et al. 2016, 2017a, b Fo forsterite content, Mg# molar 100 Mg/(Mg + Fe), Cr# 100...lamellae of clinopyroxene and vice versa. The forsterite (Fo) content of olivine varies from 86.5 to 90...(Lorand et al. 2003; Reisberg et al. 2004) and Tanzania (Chesley et al. 1999; Burton et al. 2000) (Fig |
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(1995) The Journal of Gemmology Vol. 24 (8) Gem-A |
Journal (issue) |
| responsible for optical effects are described. As yet the region has not yielded a corundum crystal large enough...plant matter or dead animals can penetrate this region (Gubelin, 1987) unless forced by some external...intruded sand grain which somehow had penetrated the region between the shell and the shellbuilding ectoderm...cabochon-cut examples of the following gems from Tanzania and Kenya: almandine, apatite, aquamarine, beryl... asterism, cabochon, inclusions. Introduction Tanzania and Kenya now contribute significantly to the |
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(2015) The Journal of Gemmology Vol. 34 (8) Gem-A |
Journal (issue) |
| Chondrodite from Tanzania| Purple garnets from East Africa |
Green prase opal from Tanzania |
Trapiche ruby...Mozambique |
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(2023, Spring) Gems & Gemology Vol. 59 (1) Gemological Institute of America |
Journal (issue) |
| fancy sapphire from Greenland • Liberian ruby • Forsterite in purple Tanzanian spinel • Grayish blue CVD...similarities with those from Umba and Songea in Tanzania, but it is generally straightforward to separate...well as 19 sapphires from Songea, Tanzania, and 17 from Umba, Tanzania. The Songea and Umba sapphires were...They were set in place using wax to allow the same region of the sample to be measured before and after heat...Canada, and Mexico. The volcanic formations in the region of the sapphire deposits are related to the late |
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(2012, Spring) InColor 19. International Colored Gemstones Association |
Journal (issue) |
| eventually craze, the material from the Wollo Province region is considerably more stable. Francesco Mazzero... Most notably, the newer deposits in the Wollo region are testing out to be much more durable than those...treatments is logical as all of the opal from this region is termed hydrophane. Hydrophane has the ability...ruby production (Image 1) between Kenya (52%), Tanzania (28%) and Madagascar (9%), in addition to 42%...spinel producers are Burma, Sri Lanka, Tajikistan, Tanzania, Madagascar and Vietnam. The T he determination |
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(2022) The Journal of Gemmology Vol. 38 (7) Gem-A |
Journal (issue) |
| The mining areas are distributed across a wide region extending from south-western to east-central Nigeria...deposit that is reportedly situated in the Calabar region of southeastern Nigeria. Calabar is located in...tourmaline-bearing pegmatites are widespread in this region, where they are hosted by basement rocks of the...obtained a parcel of rough tourmaline from the Calabar region that weighed 470 g. It consisted of broken pieces...Figure 3: This map of the Banjarmasin–Martapura region of South Kalimantan shows the location of the diamond |
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(2011, Spring) InColor 16. International Colored Gemstones Association |
Journal (issue) |
| the tsavorite project in the Manyara region of northeast Tanzania, about 20 kilometers from its tanzanite...following similar actions taken by South Africa and Tanzania. The new firm is expected to be up and running...Attapeu.) This is the infamous “Golden Triangle” region, where the borders of Thailand, Laos, and Myanmar...so-called ”emerald belt” in the Itabira-Nova Era region (Figure 2). History The discovery of emeralds...emerald belt is located in the Santa Maria de Itabira region in the southwestern corner of the map. www.gemstone |
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(2012, Fall/Autumn) InColor 21. International Colored Gemstones Association |
Journal (issue) |
| Rare ‘Haüyne’ Ethical Mining and Fair Trade Tanzania: Ethical Initiatives and CSR Synergies Jewelry...Zhuang Myanmar President Thein Sein. Autonomous Region. More than 90 companies from Myanmar displayed...largest buyer of tanzanite in the world, has visited Tanzania for the first time. Gad, who reportedly buys 70...“Diamonds International is committed to the people of Tanzania and we appreciate the opportunity of being able...tanzanite from the only source in the world. “Being in Tanzania and seeing the beautiful people we are now even |
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(2004, April) Gems & Gemology Vol. 40 (1) Gemological Institute of America |
Journal (issue) |
| pink-orange spinel from Tanzania • Large tsavorite and green grossular from Tanzania • Color-change glass...is produced at low pressures, typically in the region of one-tenth of atmospheric pressure, from carbon-con-...grown on a substrate held at a temperature in the region of 800–1000°C. For many industrial applications...carried out at temperatures and pressures (in the region of GEMS & GEMOLOGY SPRING 2004 3 Figure 2...absorption could be detected in the one-phonon region of the infrared spectrum and the material was therefore |
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(2009, July) Gems & Gemology Vol. 45 (2) Gemological Institute of America |
Journal (issue) |
| “Sugarcane Emerald” from Brazil • Orange kyanite from Tanzania • Rare optical phenomenon in play-of-color opal...Dona Dirlam wrote part of her 1992 “Gem Wealth of _Tanzania_” article sitting at my backyard patio table, while...gemological occurrence of pegmatitic gems in the region, as well as research. Based on his decade of experience...Dirlam et al. surveyed the colored stone wealth of Tanzania. Adolph Peretti and coauthors provided the authoritative...~300 nm and absorbed strongly in parts of the IR region (specifically the range 7000–20000 nm). The smaller |
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(2007) The Journal of Gemmology Vol. 30 (5-6) Gem-A |
Journal (issue) |
| storage, emitter devices in the blue and ultraviolet region, and piezoelectronic devices (Nause et al., 1999)...absorption from the visible to the ultraviolet region, which is superimposed on the iron absorption bands...(Raeside, 1989), considered the oldest rocks in the region. For example, the migmatite within a gneiss complex... Dolomite Sillimanite Epidote Sphalerite Forsterite Sphene Garnet (‘grandite’) Spinel Goethite...amphibolite grade facies (Chatterjee, 1977). Forsterite (usually heavily serpentinized), diopside, and |
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