 | | Journal (article/letter/editorial) | | the characteristics of some C- and CT-opals from Brazil F. Caucia, C. Ghisoli and I. Adamo With 5 figures...properties of blue and fire opals found in Piauí state, Brazil, have been characterized through optical...shown by some blue specimens. Key words: gems, fire opal, spectroscopic analyses, trace elements, play of...eschweizerbartxxx ingenta Introduction Opals from Brazil The opals of Brazil are a rather recent discovery. In fact...the discovery of opal in the Brazilian area has been reported, even if white noble opal has been apparently |  | | Journal (article/letter/editorial) | | micro-crystalline (C and CT) and non-crystalline (A) opal samples is here presented. The suite of the investigated...consists of the most important natural and synthetic opal samples, with a gemological significance, present...including both with and without play of color. The opal-C type is clearly identifiable on the basis of the...peak at about 620 cm–1, whereas the FTIR spectra of opal-CT and -A differ mainly for the position of the...Other phases, such as i.e. clay minerals, present in opal samples and related to different genesis and localities |  | | Report (issue) | | Diffraction Pattern: Near the Piauí river, Itinga county, Minas Gerais, Brazil. 5.98 (100), 9.98 (90), 3...12.12 100.00 (1) Near the Piauí river, Itinga county, Minas Gerais, Brazil; average electron microprobe...mineral, opal. Distribution: From a pegmatite near the Piauí river, Itinga county, Minas Gerais, Brazil. Name:...Material: Geology Museum, University of São Paulo, Brazil (DR 591). References: (1) Chukanov, N.V., D. Atencio...roscherite-group mineral from Itinga, Minas Gerais, Brazil. New Data on Minerals. 42, 11-15. Mineralogical |  | Chukanov, Nikita V., Atencio, Daniel, Zadov, Alexander E., Filho, Luis A.D. Menezes, Coutinho, Jose M.V. (2007) Guimarãesite, a New Zn-dominant Monoclinic Roscherite-group Mineral from Itinga, Minas Gerais, Brazil. New Data on Minerals, 42. 11-15 | Journal (article/letter/editorial) | | ROSCHERITEGROUP MINERAL FROM ITINGA, MINAS GERAIS, BRAZIL* Nikita V. Chukanov Institute of Problems of Chemical...Geociê ncias, Universidade de Sã o Paulo, Sã o Paulo,Brazil; datencio@usp.br Aleksander E. Zadov NPO "Regenerator"...Esmeralda, 534, Prado, 30410080, Belo Horizonte, MG, Brazil José M.V. Coutinho Instituto de Geociê ncias,... Universidade de Sã o Paulo, Sã o Paulo,Brazil; datencio@usp.br G u i m a r ã e s i t e 1 , Ca2(Zn,Mg...granite pegmatite near the Piauí river, Itinga county, Minas Gerais, Brazil. Associated minerals are: |  | | Journal (article/letter/editorial) | | 共XRPD兲 methodology, by analysing 75 new samples of opal came from different worldwide areas, is introduced...3478554兴 Key words: cristobalite, tridymite, opal C, opal CT, opal A, order-disorder, sepiolite, palygorskite...quartz, in different samples of common opal, fire opal, and wood opal. Levin and Ott 共1932, 1933兲 also highlighted...increasing interest of the scientific community about the opal crystallinity, several investigations were carried...unexplained how, in the same microcrystalline sample of opal, both the high- and low-temperature phases of cristobalite |  | | Journal (issue) | | Cat’s-eye leifite from Canada • Play-of-color opal from Brazil • Prehnite from Tanzania • Colorado rhodochrosite...“‘Paraíba’-type Copper-bearing Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting...PLACE “PARAÍBA”-TYPE COPPER-BEARING TOURMALINE FROM BRAZIL, NIGERIA, AND MOZAMBIQUE: CHEMICAL FINGERPRINTING...at Ouro Preto Federal University, Minas Gerais, Brazil. 2 MOST VALUABLE ARTICLE AWARD Ahmadjan Abduriyim...amethyst and citrine crystal “cathedrals” from Brazil in figure 3, which were on display at the JG & |  | | Journal (article/letter/editorial) | | PrePub Article 2 Near infrared signature of opal and chalcedony as a proxy for their structure and...RONDEAU and NICOLAS MANGOLD 1 4 Abstract: Opal-A, opal-CT and chalcedony develop in various geological...several new spectroscopic criteria distinguish opal-A, opal-CT and chalcedony: the apparent maximum of the...method quickly assesses the geological conditions of opal formation (on Earth or other terrestrial planets)...precipitation. Several types of opal are defined according to their internal structure: opal-A (for amorphous) can |  | | Book | | until he managed to reach the land of his dreams, Brazil. A specialist in the field of geology and mineralogy...crystals and the remarkable mineral treasures of Brazil, as well as the incredible adventures and difficulties...UNIQUE MINERALS IN WORLD MUSEUMS GEM TREASURES OF BRAZIL Cyan Magenta Yellow Black 1 Delev Ilia Deleff...UNIQUE MINERALS IN WORLD MUSEUMS GEM TREASURES OF BRAZIL SOFIA–MOSCOW 2004 3 Cyan Magenta Yellow Black...MINERAL TREASURES OF BRAZIL 76 85 AN OUTLINE OF THE MINERAL RESOURCES OF BRAZIL ORIGIN OF GIANT CRYSTALS |  | | Journal (issue) | | Articles 708 Coloured Stone Mining and Trade in Brazil: A Brief History and Current Status By Aurélien...Collection V. L. Villani photo p. 758 Cover Photo: Brazil is the source of a variety of coloured stones,...Junior (BC Gemas do Brasil, Governador Valadares, Brazil), and heating to 500°C in air was successful in...unusual materials such as labradorite, moonstone and opal. Figure 22: In the late 1800s, Wilhelm Schmidt...it is likely to have been Rio Grande do Sul in Brazil, well known for its amethyst, agate and jasper |  | | Journal (issue) | | geology, and notable localities of diamond mining in Brazil, and outlines plans for future diamond production...in bastnäsite • Flashes and flames in Ethiopian opal • Cat’s eye imitation pen pearls • Negative crystals... Svisero, James E. Shigley, and Robert Weldon Brazil, which commanded global production in the 1700s...Gerais and Mato Grosso, are presented. W hile Brazil is widely known for the production of colored gemstones...deposits. According to Kimberley Process statistics, Brazil produced 31,825 carats in 2015, although this figure |  | | Journal (issue) | | gem localities • New opals from Brazil • Bicolored spessartine from Brazil • Pink/yellow spodumene from...and the staff of Amsterdam Sauer Rio de Janeiro, Brazil RTL TRIBUTE GEMS & GEMOLOGY FALL 2002 207 ...together with rutile needles in a brown beryl from Brazil showing asterism (W. F. Eppler, “Notes on asterism...titanium. Prior to Eppler (1958), brown beryl from Brazil was described by J. Sinkankas (“Some freaks and...unknown. The absorption spectra of brown beryl from Brazil were studied by C. J. Cristino (“Utilisation des |  | | Book (edition) | | Data (CIP) (Information Sectorial Nucleus, SP, Brazil) I59 IBGM. Handbook of Gems / IBGM, DNPM. – 4...I. Title. CDU 549.091 Federative Republic of Brazil Ministry of Mines and Energy National Department...respect to the most commonly found and traded gems in Brazil. Such information is generally described in documents...to disclose our vast gemological assets both in Brazil and abroad. Therefore, this publication covers...65 Moldavite 66 Morganite 67 Obsidian 68 Onyx 69 Opal 70 Orthoclase Feldspar 71 Paraiba Tourmaline 72 |  | | Journal (issue) | | MARKETS Figure 9. Near Nova Era in Minas Gerais, Brazil, the Belmont mine operates using sophisticated...other mines in the area slowed (Weldon, 2006). Brazil witnessed a sustained slump in overall gemstone...in places like the United Arab Emirates, Russia, Brazil, India, and China—locations that would not have...discovered in Paraíba and Rio Grande do Norte states in Brazil in 1989 (Fritsch et al., 1990) and became known...plummeted, mining operations in key centers such as Brazil and Zambia curtailed or ceased production, though |  | | Journal (issue) | | parcels of amethyst, aquamarine, and Mexican fire opal, to name just a few examples. Careful manipulation...Jeff Scovil, © Anglo Swiss Resources, Inc. orange opal. The deposit was first found about three years ago...resemble those of Jupiter and Saturn. Opal in matrix from Brazil. Carlos Vasconcelos of Vasconcelos Brasil...samples of opal with good play-of-color (figure 17) from a new deposit near Tranqueira in Piauí State, northern...northern Brazil. The area lies about 200 km south of previously known opal deposits in Piauí, and was |  | | Journal (issue) | | spectroscopy. 120 Gem-Quality Andalusite from Brazil Shyamala Fernandes and Gagan Choudhary Documents...Emerald” from Brazil • Orange kyanite from Tanzania • Rare optical phenomenon in play-of-color opal • Cultured...“Gemstones and the Spectroscope” series. Minas Gerais, Brazil, supplied most of the world’s market In the 1940s...GEMOLOGY SUMMER 2009 as the play-of-color in opal and the blue sheen of moonstone feldspars. Summer...Tourmalines from São José da Batalha, Paraíba, Brazil.” The introduction of exceptionally bright blue |  | | Book | | original: Norte-Americano: “GEOLOGY AND PHYSICAL OF BRAZIL” GEOGRAPHY Esta tradução & propriedade literarta...publicação da obra “Geology and Physical Geography of Brazil”, pasa satisfazer ao pedido de Louis Agassiz para...1868— (Accowt of o lecture ou the glaciotion of Brazil”) (“Resumo de uma conferência sobre à glaciação...PHYSICAL GEOGRAPHY OF BRAZIL” (Thayer Expedition-Scientific "results of a journey in Brazil by Louis Agassiz...dessa excursão foi publicada na obra “Journey in Brazil”, (*) não sendo, portanto, necessário repeti-lo |  | | Journal (issue) | | India Bhadresh Pandit, Tanzania Clement Sabbagh, Brazil Capt. Ramji Sharma, Japan Avner Sofiov, Israel...this year, ICA president Andrew Cody visited the Brazil Gem Show where he made a donation on behalf of...jewelry manufacturing in other countries. Today, Brazil is developing a reputation for the same high-quality...develop around larger stones, such as cabochons. Brazil is among the largest Oscar Niemeyer Copan ring...imperial topaz. In addition to imperial topaz, Brazil also has unique stones, such as Paraíba Tourmaline |  | | Book (edition) | | 22 23 24 25 26 27 28 29 30 31 Spodumene Quartz Opal Turquoise Lapis Lazuli Jade – Geology and Mineralogy...Gemstones’ becoming ‘Colour and Colour Enhancement’, and ‘Opal’ xiii Preface to the Fifth Edition being extracted...Pierre Gilson including, most importantly, synthetic opal, both white and black, and a corresponding ingenuity...stone’, a special type of glass closely resembling opal in appearance. Quartz, which for many years has...ft) thick at Urubu, near Araçuai, Minas Gerais, Brazil. Fine pink and green gem-quality tourmaline has |  | | Journal (issue) | | Namibia, as well as Madagascar), South America (Brazil and Colombia), central and southern Asia (Sri Lanka...Pakistan; and pink to red tourmalines from Nigeria and Brazil. Diamond was mined in northern Canada for the first...diamond, garnet, jade [both jadeite and nephrite], opal, peridot, quartz, spinel, tanzanite, topaz, and...mining also continued at traditional sources in Brazil and Africa. Large quantities of Brazilian emeralds...reserves and reduced demand. Emerald production in Brazil has since continued to decline. Several sources |  | | Journal (issue) | | Brazilian blue “opal” • Otolith pendant • Inclusions in quartz from Paraíba, Brazil • Sinhalite from...Tourmalines from New Deposits in Paraíba State, Brazil” for the journal’s Fall 2007 issue (pp. 236–239)...of “Paraíba-type Copper-bearing Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting...green portion of a colorzoned Mn-poor sample from Brazil (R060566; R. Downs, pers. comm., 2007). The origin...only significant diamond sources were India and Brazil. Paltscho does not describe the GEMS & GEMOLOGY |  | | Journal (issue) | | Kevin Schumacher Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia...sapphires • Lazurite in spinel • Fossil insect in opal • Trapiche-like ruby from the Batakundi mine in...118 Gem News International Tucson 2019 • Boulder opal mining • Brazilian alexandrite • Cat’s-eye nephrite...and a 3.20 ct Paraíba tourmaline trillion from Brazil. The rings and loose stones are courtesy of Omi...grandidierite inclusions in sapphire, and a fossil insect in opal. Our Gem News International section has more than |  | | Journal (issue) | | • CVD synthetic diamond • “Mermaid Crystal,” an opal simulant • Synthetic spinel with unusual inclusions...the recognition of sugar-acid treatment of porous opal, spectroscopic studies of diamonds and their origin...yellow diamond Treated yellow sapphires Black treated opal Pink diamond Cultured pearls with pink dye Treated...cat's-eyes Treated jadeite bead necklace Emeralds from Brazil Famous diamond Pink conch pearl Color-change sapphire...pink diamonds Maxixe blue beryl Gilson synthetic opal Yellow conch pearl Taaffeite Cubic zirconia Cultured |  | | Journal (issue) | | amber imitation • Assembled diamond imitations from Brazil • Enamel-backed quartz as a star sapphire imitation...such as the fibrous structure in some cat’s-eye opal, or by other phenomena, such as the oriented adularescence...Also presented were the results of exploration in Brazil and in the Wawa and James Bay Lowland areas of...INTERNATIONAL Figure 9. This 19.39 ct amethyst from Brazil displays chatoyancy. Photo by Jaroslav Hyrsl. ...1996). Alfred A. Levinson Cat’s-eye amethyst from Brazil. Amethyst is one of the more common gems, but it |  | | Journal (issue) | | mine, Bolivia • Andradite from China • Barite from Brazil • Gem hanksite • Lepidolite beads • “Soufflé” freshwater...freshwater cultured pearls • “Churrasco quartz” from Brazil • Cat’s-eye rhodonite • Large H-rich diamond •...Online: Spring 2006 “Paraíba”-type Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting...Synthetic Blue Beryl A New Type of Synthetic Fire Opal: Mexifire The Color Durability of “Chocolate Pearls”...“Chocolate Pearls” Treated by Ballerina Pearl Co. Leopard Opal from Mexico The Cause of Iridescence in Rainbow |  | | Journal (issue) | | Pearl Testing 36 Emeralds from South America – Brazil and Colombia 48 Clinohumite – The Mountain Fire...rise of new economies such as China, India, and Brazil. The challenges have been numerous as these new...every ICA member, I would like to thank the IBGM in Brazil along with every company, individual, and government... G E M O LO G Y Emeralds from South America – Brazil and Colombia By Dr. Dietmar Schwarz, research manager...terms of size and variety of gemstone deposits, Brazil can be considered as a large gemological province |
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Boi Morto mine, Pedro II, Piauí, Brazil