DOCSLIB.ORG

Gemmologythe Journal of Volume 35 / No

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Gemmologythe Journal of Volume 35 / No GemmologyThe Journal of Volume 35 / No. 8 / 2017 The Gemmological Association of Great Britain Contents GemmologyThe Journal of Volume 35 / No. 8 / 2017 COLUMNS p. 702 687 What’s New D-Scope+ microscope|EXA spectrometer|GIA iD100 gem testing device|Melee Inspector| Presidium Synthetic Diamond p. 713 Screener II|SYNTHdetect mounted diamond screen- ing device|CIBJO Congress reports|Canadian diamond anniversary|GRS colour terms| Jordan Wilkins photo GSA gem abstracts| Margaritologia pearl news- letter|Santa Fe Symposium proceedings|Fei cui testing in Hong Kong ARTICLES 691 Gem Notes A. Reys photo Baryte from South Dakota, USA| Feature Articles Gems from Mong Long, Myan- mar|Pyrite and other sulphides 708 Coloured Stone Mining and Trade in Brazil: from Peru|Purple spinel from A Brief History and Current Status Badakhshan, Afghanistan| By Aurélien Reys Windmill-cut topaz from Nam- ibia|Tourmaline from Masisi, DRC|Yellow tourmaline from 728 Radiocarbon Age Dating of 1,000-Year-Old Pearls Mavuco, Mozambique|Tremolite from the Cirebon Shipwreck (Java, Indonesia) from Tanzania|Tsavorite from By Michael S. Krzemnicki, Laurent E. Cartier and Irka Hajdas Ethiopia|Black star CZ sold as natural star rutile|Cameos at the Natural History Museum 738 Naming of the Koh-i-Noor and the Origin of Mughal-Cut Diamonds By Anna Malecka 752 Characterization of Mexican Amber from the Yi Kwan Tsang Collection By Vittoria L. Villani, Franca Caucia, Luigi Marinoni, Alberto Leone, Maura Brusoni, Riccardo Groppali, Federica Corana, Elena Ferrari and Cinzia Galli V. L. Villani photo p. 758 Cover Photo: 766 Conferences Brazil is the source of a va- Dallas Mineral Collecting Symposium|World of Gems Conference V| riety of coloured stones, as Gem-A Conference|World Ruby Forum described in the article by A. Reys on pp. 708–726 of this issue. Shown here are several custom-cut Brazil- 772 Gem-A Notices ian gems consisting of a 9.69 ct morganite, 12.73 ct Swiss Blue topaz, 7.99 ct 786 Learning Opportunities amethyst, 3.29 ct tourma- line, 2.40 ct aquamarine, 1.12 ct Imperial topaz and 790 New Media 4.84 ct golden beryl. Courtesy of John Dyer Gems; composite photo by Ozzie Campos. 794 Literature of Interest The Journal is published by Gem-A in collaboration with SSEF and with the support of AGL and GIT. ISSN: 1355-4565, http://dx/doi.org/10.15506/JoG.2017.35.8 i The Journal of emmology G THE GEMMOLOGICAL ASSOCIATION OF GREAT BRITAIN Editor-in-Chief Production Editor Marketing Consultant Brendan M. Laurs Mary A. Burland Ya’akov Almor [email protected] [email protected] [email protected] 21 Ely Place Executive Editor Editor Emeritus Editorial Assistants London EC1N 6TD Alan D. Hart Roger R. Harding Carol M. Stockton Sarah Salmon UK Associate Editors t: +44 (0)20 7404 3334 Ahmadjan Abduriyim, Tokyo Gem Science, Tokyo, Japan; Raquel Alonso-Perez, Harvard Univer- f: +44 (0)20 7404 8843 sity, Cambridge, Massachusetts, USA; Edward Boehm, RareSource, Chattanooga, Tennessee, USA; e: [email protected] Maggie Campbell Pedersen, Organic Gems, London; Alan T. Collins, King’s College London; John w: www.gem-a.com L. Emmett, Crystal Chemistry, Brush Prairie, Washington, USA; Emmanuel Fritsch, Uni- versity of Nantes, France; Rui Galopim de Carvalho, Portugal Gemas, Lisbon, Portugal; Lee Registered Charity No. 1109555 A. Groat, University of British Columbia, Vancouver, Canada; Thomas Hainschwang, A company limited by guarantee and GGTL Laboratories, Balzers, Liechtenstein; Henry A. Hänni, GemExpert, Basel, Switzer- registered in England No. 1945780 land; Jeff W. Harris, University of Glasgow; Alan D. Hart, Gem-A, London; Ulrich Henn, Registered office: Palladium House, German Gemmological Association, Idar-Oberstein; Jaroslav Hyršl, Prague, Czech Repub- 1–4 Argyll Street, London W1F 7LD lic; Brian Jackson, National Museums Scotland, Edinburgh; Stefanos Karampelas, Bah- rain Institute for Pearls & Gemstones (DANAT), Manama, Kingdom of Bahrain; Lore Kiefert, Gübelin Gem Lab Ltd., Lucerne, Switzerland; Hiroshi Kitawaki, Central Gem Labo- ratory, Tokyo, Japan; Michael S. Krzemnicki, Swiss Gemmological Institute SSEF, Basel; Shane F. McClure, Gemological Institute of America, Carlsbad, California; Jack M. Ogden, President Striptwist Ltd., London; Federico Pezzotta, Natural History Museum of Milan, Italy; Jeffrey Maggie Campbell Pedersen E. Post, Smithsonian Institution, Washington DC, USA; Andrew H. Rankin, Kingston Univer- sity, Surrey; Benjamin Rondeau, University of Nantes, France; George R. Rossman, Califor- Vice Presidents nia Institute of Technology, Pasadena, USA; Karl Schmetzer, Petershausen, Germany; Diet- David J. Callaghan mar Schwarz, Federated International GemLab, Bangkok, Thailand; Menahem Sevdermish, Alan T. Collins Gemewizard Ltd., Ramat Gan, Israel; Guanghai Shi, China University of Geosciences, Bei- jing; James E. Shigley, Gemological Institute of America, Carlsbad, California; Christopher Noel W. Deeks P. Smith, American Gemological Laboratories Inc., New York, New York; Evelyne Stern, Lon- E. Alan Jobbins don; Elisabeth Strack, Gemmologisches Institut Hamburg, Germany; Tay Thye Sun, Far East Andrew H. Rankin Gemological Laboratory, Singapore; Pornsawat Wathanakul, Kasetsart University, Bangkok, Thailand; Chris M. Welbourn, Reading, Berkshire; Bert Willems, Leica Microsystems, Wetz- Honorary Fellows lar, Germany; Bear Williams, Stone Group Laboratories LLC, Jefferson City, Missouri, USA; Gaetano Cavalieri J.C. (Hanco) Zwaan, National Museum of Natural History ‘Naturalis’, Leiden, The Netherlands. Andrew Cody Terrence S. Coldham Content Submission Emmanuel Fritsch The Editor-in-Chief is glad to consider original articles, news items, conference/excursion reports, announcements and calendar entries on subjects of gemmological interest for Honorary Diamond Member publication in The Journal of Gemmology. A guide to the various sections and the preparation Martin Rapaport of manuscripts is given at www.gem-a.com/index.php/news-publications/publications/ journal-of-gemmology/submissions, or contact the Production Editor. Chief Executive Officer Subscriptions Alan D. Hart Gem-A members receive The Journal as part of their membership package, full details Council of which are given at www.gem-a.com/membership. Laboratories, libraries, museums and Justine L. Carmody – Chair similar institutions may become direct subscribers to The Journal. Kathryn L. Bonanno Advertising Lesley Exley Enquiries about advertising in The Journal should be directed to the Marketing Consultant. Paul F. Greer For more information, see www.gem-a.com/index.php/news-publications/publications/ Kerry H. Gregory journal-of-gemmology/advertising. Joanna Hardy Nigel B. Israel Database Coverage Jack M. Ogden The Journal of Gemmology is covered by the following abstracting and indexing services: Philip Sadler Australian Research Council academic journal list, British Library Document Supply Christopher P. Smith Service, Chemical Abstracts (CA Plus), Copyright Clearance Center’s RightFind ap- plication, CrossRef, EBSCO (Academic Search International, Discovery Service and Branch Chairmen TOC Premier), Gale/Cengage Learning Academic OneFile, GeoRef, Index Copernicus Midlands – Georgina E. Kettle ICI Journals Master List, Mineralogical Abstracts, Cambridge Scientific Abstracts (ProQuest), North East – Mark W. Houghton Scopus and the Thomson Reuters’ Emerging Sources Citation Index (in the Web of Science). South East – Veronica Wetten Copyright and Reprint Permission South West – Richard M. Slater For full details of copyright and reprint permission contact the Editor-in-Chief. The Journal of Gemmology is published quarterly by Gem-A, The Gemmological Association of Great Britain. Any opinions expressed in The Journal are understood to be the views of the contributors and not necessarily of the publisher. Printed by DG3 (Europe) Ltd. © 2017 The Gemmological Association of Great Britain Understanding Gems ™ ISSN: 1355-4565 Cert no. TT-COC-002454 ii The Journal of Gemmology, 35(8), 2017 What’s New INSTRUMENTATION D-Scope+ Microscope corundum, alexandrite, tanzanite, zircon, Imperial Introduced in September 2017, the D-Scope+ mi- topaz and emerald (and its most common fillers). croscope from HRD Antwerp is specially designed The unit measures 23 × 21 × 13 cm, weighs 3.3 for use with diamonds. Improvements on HRD’s kg and can be upgraded for additional applications. original D-Scope include its il- For more information, visit www.gemmoraman. lumination, ease of use, and com/Products/EXA.aspx. ergonomics. The user can Alberto Scarani and Mikko Åström choose from three colours of Magilabs, Helsinki, Finland and Rome, Italy darkfield lighting: yellowish, white daylight, and strong white light. The controls to GIA iD100 Gem Testing Device manipulate a stone have In April 2017, the Gemological Institute of America been redesigned to improve announced a new spectrosco- comfort, and the manipula- py-based desktop instrument tion table can be moved up and down to achieve for the screening of natural proper focus. For additional information, visit www. diamonds from simulants and hrdantwerp.com/en/product/new-d-scope. CMS synthetic (HPHT and CVD) or treated diamonds. Stones 0.9 mm in diameter (approximately EXA Spectrometer 0.005 ct) or greater, either loose In November 2017, Magilabs released the EXA, a or mounted, can be tested by pointing the probe standalone spectrometer unit able to quickly identi- at the sample. Within two seconds, the device dis- fy natural diamonds and other gems by their fluores-
Load more

Recommended publications
  • A New Sulphosalt Mineral from Lengenbach, Binntal (Switzerland)
    Jentschite (TIPbAs2SbS6) - a new sulphosalt mineral from Lengenbach, Binntal (Switzerland) STEFAN GRAESER Natural History Museum CH-4001 Basel and Mineralogical Institute, University of Basel, CH-4056 Basel, Switzerland AND ANDREAS EDEN HARTER Institut fiir Mineralogie und Kristallographie, Universitat Gottingen, 0-37077 Gottingen, Germany Abstract Jentschite, TlPbAs2SbS6, is a new sulphosalt mineral from the famous Lengenbach locality (Binntal, Switzerland). It was discovered in association with numerous other TI-As-sulphosalts such as hutchinsonite, wallisite-hatchite, edenharterite, bemardite, abundant realgar and orpiment in small cavities in a dolomitic rock of Triassic age which forms part of the Penninic Monte-Leone-nappe. The first specimens consisted of extremely small polysynthetically twinned crystals; a later find yielded less complicated twinned crystals in sizes up to 2 mm length.oSingle crystal X-ray diffraction st~dies gave a monoclinic cell with a =8.121(3), b = 23.969(9), c =5.847(3) A, B= 107.68(W, V = 1084.3(5) A3, Z = 4, space group P21/n. The strongest lines in the X-ray powder diagram are (dobsin A, lobs'hkl): 2.823 (100)(116), 3.587 (86)(221), 2.778 (84)(260), 3.998 (74)(060), 2.670 (58)(301), 3.816 (54)(210). Chemical composition (electron microprobe, mean of 15 analyses, wt.%) is: TI 23.92, Pb 21.44, As 19.16, Sb 12.53, S 22.42, total 99.47 wt.% from which a simplified formula TIPbAs2Sb1S6 can be derived. This formula is very close to that of the (orthorhombic) mineral edenharterite TIPbAs3S6. From structural and chemical data it was interpreted as the ordered structure of an Sb-bearing relative of edenharterite, a postulation that meanwhile could be confirmed by the complete structure determinations of both, edenharterite and jentschite (Berlepsch, 1996).
    [Show full text]
  • Peace & Conflict Update – October 2017
    PEACE & CONFLICT UPDATE – OCTOBER 2017 Updates archive: http://www.burmalink.org/peace-conflict-updates/ Updates archive: https://www.burmalink.org/peace-process-overview/ ACRONYM DICTIONARY AA Arakan Army ALP Arakan Liberation Party BA Burma Army (Tatmadaw) CSO Civil Society Organisation DASSK Daw Aung San Suu Kyi EAO Ethnic Armed Organisation FPNCC Federal Political Negotiation Consultative Committee IDP Internally Displaced Person KBC Karen Baptist Convention KIA Kachin Independence Arm, armed wing of the KIO KIO Kachin Independence Organization KNU Karen National Union MoU Memorandum of Understanding MNEC Mon National Education Committee MNHRC Myanmar National Human Rights Commission NCA Nationwide Ceasefire Agreement (in name only, not inclusive and not nationwide) NLD National League for Democracy NRPC National Reconciliation and Peace Center PC Peace Commission PPST Peace Process Steering Committee (NCA negotiating body) SSPP/SSA-N Shan State Progress Party/Shan State Army (North) TNLA Ta'ang National Liberation Army UN United Nations UNFC United Nationalities Federal Council UPC Union Peace Conference UPDJC Union Peace Dialogue Joint Committee UWSA United Wa State Army 21CPC 21st Century Panglong Conference OCTOBER HIGHLIGHTS • Over 600,000 Rohingya have been displaced since the August 25 attacks and subsequent 'clearance operations' in Arakan (Rakhine). Talks of repatriation of Rohingya refugees between Burma and Bangladesh have stalled, and many Rohingya refugees reject the prospect of returning in the light of unresolved causes to the violence, and fears of ongoing abuse. • Displaced populations on the Thailand-Burma border face increasing challenges and humanitarian funding cuts. As of October 1, TBC has stopped distributing food aid to Shan IDP camps and the Ei Tu Hta Karen IDP camp.
    [Show full text]
  • Secretaria De Estado De Ciência, Tecnologia E Ensino Superior
    66 – terça-feira, 27 de outubro de 2015 diário do exeCutivo Minas Gerais - Caderno 1 decisão prolatada pelo STF nos autos da ADI nº 4876, dos servido- RETIFICAÇÃO – ATO Nº 04/2015 7-01, Marli Gonçalves de Abreu, PEBIM, por 01 mês, referente ao 1º cação dos documentos para guarda permanente e a eliminação daqueles res: ABAETÉ- EE . Dr . Edgardo da Cunha Pereira, MaSP 982 .051-5, RETIFICA, no Ato de Adicional por tempo de serviço referente ao quinquênio de exercício, a partir de 16/11/15; EE Stella Abrantes, Masp destituídos de valor probatório e informativo; Vilma Gláucia da Silva Maia, a partir de 27 .10 .15, referente ao cargo servidor: BIQUINHAS- EE . Sorama Geralda Richard Xavier, MaSP 1048615-7-01, Sheila Alves Afonso, EEBIE, por 01 mês, referente ao II – Propor métodos de arquivamento voltados ao melhor aproveita- de ASBI C, admissão 01, em vista do requerimento de aposentadoria 311 .936-9, Ronaldo José da Silva, ASBIII J, admissão 01, Ato nº 2º quinquênio de exercício, a partir de 16/11/15; JUNCO DE MINAS/ mento do espaço físico disponível nas unidades; pelo art . 40 §1º, inciso III, alínea “b” da CF/88, com redação dada pela 35/2010, publicado em 17 .08 .10 por incorreção, onde se lê: a partir de MALACACHETA – EE Geraldo dos Santos Coimbra, Masp 638953- III – Submeter-se às normas, instruções e procedimentos expedidos EC 41/03, com direito à média das remunerações de contribuição de 25 .01 .10, leia-se: a partir de 11 .11 .09 . 0-01, Rédina Cordeiro Amaral Moreira, PEBTIG, por 01 mês, refe- pelas Instituições Arquivísticas Públicas de Minas Gerais, no âmbito de 4 .204 dias de exercício, sendo a última remuneração correspondente à rente ao 3º quinquênio de exercício, a partir de 18/11/15; NANUQUE sua esfera de atuação, bem como as do Conselho Estadual de Arquivos carga horária de 135 horas; DORES DO INDAIÁ- EE .
    [Show full text]
  • Depósitos De Alexandrita De Malacacheta, Minas Gerais*
    GEONOMOS 8 (1): 47-54 DEPÓSITOS DE ALEXANDRITA DE MALACACHETA, MINAS GERAIS* Márcio Silva Basílio1,2, Antônio Carlos Pedrosa-Soares3; Hanna Jordt-Evangelista1 ABSTRACT Since 1975, alexandrite [Be(Al2-xCrx)2O4], the chromium-bearing crysoberyl variety, has been exploited from alluvial and paleo-alluvial deposits in the Malacacheta region. The alluvial deposits consist of resedimented gravel along the present drainage streams. The paleo-alluvial deposits are richer in alexandrite, and show well-developed soil horizons covering the alexandrite-bearing gravel layer. Alexandrite grains show angular shapes with very sharp edges, suggesting transport for short distances. The country rocks are quartz-mica schist and peraluminous mica schist (Salinas Formation), covered by alternating mica schist and quartzite layers (Capelinha Formation). Both formations are of Neoproterozoic age. They host tectonic slabs of metaultramafic rocks, and are cut by intrusive granites of Cambrian age. No alexandrite-bearing rock has been found in the area, probably due to the intense tropical weathering. However, some of the mapped rocks are sources for Be (granites), Cr (metaultramafics) and Al (peraluminous schists), the essential elements for alexandrite crystallization. We suggest a metasomatic system of Cambrian age for alexandrite genesis in the area, involving the interaction of granite-related Be-rich fluids with metaultramafic rocks and peraluminous schists. INTRODUÇÃO qualidade (Proctor 1988). Em 1985 foi descoberto um cristal pesando 14,6 g no Ribeirão Soturno que, depois Alexandrita, uma das mais raras e valiosas gemas de lapidado, gerou um cabochão de 18,5 ct, considerado do mundo, é a variedade cromífera do crisoberilo uma das mais raras e finas alexandritas olho-de-gato do (BeAl2O4).
    [Show full text]
  • Web-Book Catalog 2021-05-10
    Lehigh Gap Nature Center Library Book Catalog Title Year Author(s) Publisher Keywords Keywords Catalog No. National Geographic, Washington, 100 best pictures. 2001 National Geogrpahic. Photographs. 779 DC Miller, Jeffrey C., and Daniel H. 100 butterflies and moths : portraits from Belknap Press of Harvard University Butterflies - Costa 2007 Janzen, and Winifred Moths - Costa Rica 595.789097286 th tropical forests of Costa Rica Press, Cambridge, MA rica Hallwachs. Miller, Jeffery C., and Daniel H. 100 caterpillars : portraits from the Belknap Press of Harvard University Caterpillars - Costa 2006 Janzen, and Winifred 595.781 tropical forests of Costa Rica Press, Cambridge, MA Rica Hallwachs 100 plants to feed the bees : provide a 2016 Lee-Mader, Eric, et al. Storey Publishing, North Adams, MA Bees. Pollination 635.9676 healthy habitat to help pollinators thrive Klots, Alexander B., and Elsie 1001 answers to questions about insects 1961 Grosset & Dunlap, New York, NY Insects 595.7 B. Klots Cruickshank, Allan D., and Dodd, Mead, and Company, New 1001 questions answered about birds 1958 Birds 598 Helen Cruickshank York, NY Currie, Philip J. and Eva B. 101 Questions About Dinosaurs 1996 Dover Publications, Inc., Mineola, NY Reptiles Dinosaurs 567.91 Koppelhus Dover Publications, Inc., Mineola, N. 101 Questions About the Seashore 1997 Barlowe, Sy Seashore 577.51 Y. Gardening to attract 101 ways to help birds 2006 Erickson, Laura. Stackpole Books, Mechanicsburg, PA Birds - Conservation. 639.978 birds. Sharpe, Grant, and Wenonah University of Wisconsin Press, 101 wildflowers of Arcadia National Park 1963 581.769909741 Sharpe Madison, WI 1300 real and fanciful animals : from Animals, Mythical in 1998 Merian, Matthaus Dover Publications, Mineola, NY Animals in art 769.432 seventeenth-century engravings.
    [Show full text]
  • The Anjahamiary Pegmatite, Fort Dauphin Area, Madagascar
    The Anjahamiary pegmatite, Fort Dauphin area, Madagascar Federico Pezzotta* & Marc Jobin** * Museo Civico di Storia Naturale, Corso Venezia 55, I-20121 Milano, Italy. ** SOMEMA, BP 6018, Antananarivo 101, Madagascar. E-mail:<[email protected]> 21 February, 2003 INTRODUCTION Madagascar is among the most important areas in the world for the production, mainly in the past, of tourmaline (elbaite and liddicoatite) gemstones and mineral specimens. A large literature database documents the presence of a number of pegmatites rich in elbaite and liddicoatite. The pegmatites are mainly concentrated in central Madagascar, in a region including, from north to south, the areas of Tsiroanomandidy, Itasy, Antsirabe-Betafo, Ambositra, Ambatofinandrahana, Mandosonoro, Ikalamavony, Fenoarivo and Fianarantsoa (e.g. Pezzotta, 2001). In general, outside this large area, elbaite-liddicoatite-bearing pegmatites are rare and only minor discoveries have been made in the past. Nevertheless, some recent work made by the Malagasy company SOMEMEA, discovered a great potential for elbaite-liddicoatite gemstones and mineral specimens in a large, unusual pegmatite (the Anjahamiary pegmatite), hosted in high- metamorphic terrains. The Anjahamiary pegmatite lies in the Fort Dauphin (Tôlanaro) area, close to the southern coast of Madagascar. This paper reports a general description of this locality, and some preliminary results of the analytical studies of the accessory minerals collected at the mine. Among the most important analytical results is the presence of gemmy blue liddicoatite crystals with a very high Ca content, indicating the presence in this tourmaline crystal of composition near the liddicoatite end-member. LOCATION AND ACCESS The Anjahamiary pegmatite is located about 70 km NW of the town of Fort Dauphin (Tôlanaro) (Fig.
    [Show full text]
  • Comissão De Desenvolvimento Urbano E Interior Projeto
    COMISSÃO DE DESENVOLVIMENTO URBANO E INTERIOR PROJETO DE LEI N o 7.368, DE 2002 (Apensos: 467/2003, 2.388/2003, 6.456/2005) Altera o art. 2º da Medida Provisória nº 2.156-5, de 24 de agosto de 2001. Autor: Comissão de Legislação Participativa (SUG 55/2002) Relator: Deputado Pedro Eugênio I - RELATÓRIO O Projeto de Lei nº 7.368, de 2002, de autoria da Comissão de Legislação Participativa, elaborado a partir da SUG 55/2002, altera o art. 2º da Medida Provisória nº 2.156-5, de 24 de agosto de 2001, para acrescentar os seguintes Municípios de Minas Gerais ao Plano de Desenvolvimento do Nordeste: Água Boa, Aimorés, Alpercata, Alvarenga, Alvorada de Minas, Braúnas, Cantagalo, Capitão Andrade, Carmésia, Catuji, Central de Minas, Coluna, Conselheiro Pena, Coroaci, Cuparaque, Divino das Laranjeiras, Divinolândia de Minas, Dom Joaquim, Dores de Guanhães, Engenheiro Caldas, Fernandes Tourinho, Frei Inocêncio, Frei Lagonegro, Galiléia, Goiabeira, Gonzaga, Governador Valadares, Guanhães, Itabirinha de Mantena, Itueta, Jampruca, José Raydan, Malacacheta, Mantena, Marilac, Materlândia, Mathias Lobato, Mendes Pimentel, Nacip Raydan, Nova Belém, Nova Módica, Paulistas, Peçanha, Resplendor, Rio Vermelho, Sabinópolis, Santa Efigênia de Minas, Santa Maria do Suaçuí, Santa Rita do Itueto, Santo Antonio do Itambé, São Félix de Minas, São Geraldo da Piedade, São Geraldo do Baixio, São João do Manteninha, São João Evangelista, São José da Safira, São José do Divino, São José do Jacuri, São Pedro do Suaçuí, São Sebastião 2 do Maranhão, Sardoá, Senhora do Porto, Serra Azul de Minas, Serro, Sobrália, Tarumirim, Tumiritinga, Virginópolis e Virgolândia”. Ao Projeto de Lei nº 7.368, de 2002, foram apensadas três proposições.
    [Show full text]
  • THE CUTTING PROPERTIES of KUNZITE by John L
    THE CUTTING PROPERTIES OF KUNZITE By John L. Ramsey In the process of cutting l~unzite,a lapidary comes THE PROBLEMS OF PERFECT CLEAVAGE face-to-face with problem properties that sometimes AND RESISTANCE' TO ABRASION remain hidden from the jeweler. By way of ex- amining these problems, we present the example of Kunzite is a variety of spodumene, a lithium alu- a one-kilo kunzite crystal being cut. The cutting minum silicate (see box). Those readers who are problems shown give ample warning to the jeweler familiar with either cutting or mounting stones to take care in working with kunzite and dem- in jewelry are aware of the problems that spodu- onstrate the necessity of cautioning customers to mene, in this case kunzite, invariably poses. For avoid shocking the stone when they wear it in those unfamiliar, it is important to note that kun- jewelry. zite has two distinct cleavages. Perfect cleavage in a stone means that splitting, when it occurs, tends to produce plane surfaces. Cleavage in two directions means that the splitting can occur in The difficulties inherent in faceting lzunzite are a plane along either of two directions in the crys- legendary to the lapidary. Yet the special cutting tal. The property of cleavage, while not desirable problems of this stone also provide an important in a gemstone, does not in and of itself mean trou- perspective for the jeweler. The cutting process ble. For instance, diamond tends to cleave but reveals all of the stone's intrinsic mineralogical splits with such difficulty that diamonds are cut, problems to anyone who works with it, whether mounted, and worn with little trepidation.
    [Show full text]
  • Origin of Color in Cuprian Elbaite from Sflo Jos6 De Batalha, Paraiba, Brazil
    American Mineralogist, Volume 76, pages 1479-1484, I99I Origin of color in cuprian elbaite from Sflo Jos6 de Batalha, Paraiba, Brazil Gnoncn R. Rosslvr,tN Division of Geology and Planetary Sciences,l7O-25, California Institute of Technology, Pasadena,California 9l125, U.S.A Evrvrm.luel FnrrscH, J,lvrns E. Srncr.Bv GIA Research,Gemological Institute of America, 1660 Stewart Street,Santa Monica, California 90404-4088, U.S.A. Ansrn-q.cr Gem-quality elbaite from Paraiba, Brazil, containing up to 1.4 wt0i6Cu has been char- acterizedusing optical spectroscopyand crystal chemistry. The optical absorption spectra of Cu2t in these tourmalines consist of two bands with maxima in the 695- to 940-nm region that are more intense in the E I c direction. The vivid yellowish green to blue- greencolors of theseelbaite samplesarise primarily from Cu2*and are modified to violet- blue and violet hues by increasingabsorptions from Mn3*. IwrnooucrtoN in a small, decomposed granitic pegmatite (formerly quartz, The color of elbaite has hen extensively investigated. prospectedfor manganotantalite).The associated Most colors are determined by small amounts of transi- altered feldspar, and lepidolite have not been character- tion elements(Dietrich, 1985).In particular, blue to green ized. Most of the tourmalines occur as crystal fragments colors have been attributed to various processesinvolv- weighing less than a g.ram,although pieceslarge enough ing both Fe2*and Fe3*ions (Mattson and Rossman, 1987) to produce facetedgemstones up to 33 carats(6.6 g) have and Fe2*- Tia* chargetransfer (Mattson, as cited in Die- been found. In rare instances, small crystals are recov- trich, 1985, p.
    [Show full text]
  • Mercados Campesinos En Bogotá Y La Región Central De Colombia
    Economía campesina, soberanía y seguridad alimentarias. La experiencia de Mercados Campesinos en Bogotá y la región central de Colombia Bogotá, D. C. Noviembre de 2011 1 Contenido 1. Introducción .................................................................................................................... 4 1.1. Tierra y alimentos: problema estructural ................................................................... 16 1.2. Mercado y alimentos: encrucijada actual .................................................................. 21 1.3. Economía campesina y su participación en la economía nacional ............................ 29 1.4. Las economías indígenas y afrocolombianas ............................................................ 38 1.5. La cuestión agroalimentaria y la economía campesina ............................................. 41 1.6. Mercados Campesinos, seguridad y soberanía alimentarias. Una apuesta de economía alternativa ......................................................................................................... 46 1.7. La apuesta política de las organizaciones por Incidir en el Plan Maestro. ................ 50 2. Aspectos económicos del proceso Mercados Campesinos ........................................... 57 2.1. La canasta alimentaria de Mercados Campesinos ..................................................... 57 2.1.1. Proveniencia de los alimentos ................................................................................ 60 2.1.1.1. Estudio de caso: comportamiento del microcanal en el
    [Show full text]
  • Evaluation of Brilliance, Fire, and Scintillation in Round Brilliant
    Optical Engineering 46͑9͒, 093604 ͑September 2007͒ Evaluation of brilliance, fire, and scintillation in round brilliant gemstones Jose Sasian, FELLOW SPIE Abstract. We discuss several illumination effects in gemstones and University of Arizona present maps to evaluate them. The matrices and tilt views of these College of Optical Sciences maps permit one to find the stones that perform best in terms of illumi- 1630 East University Boulevard nation properties. By using the concepts of the main cutter’s line, and the Tucson, Arizona 85721 anti-cutter’s line, the problem of finding the best stones is reduced by E-mail: [email protected] one dimension in the cutter’s space. For the first time it is clearly shown why the Tolkowsky cut, and other cuts adjacent to it along the main cutter’s line, is one of the best round brilliant cuts. The maps we intro- Jason Quick duce are a valuable educational tool, provide a basis for gemstone grad- Jacob Sheffield ing, and are useful in the jewelry industry to assess gemstone American Gem Society Laboratories performance. © 2007 Society of Photo-Optical Instrumentation Engineers. 8917 West Sahara Avenue ͓DOI: 10.1117/1.2769018͔ Las Vegas, Nevada 89117 Subject terms: gemstone evaluation; gemstone grading; gemstone brilliance; gemstone fire; gemstone scintillation; gemstone cuts; round brilliant; gemstones; diamond cuts; diamonds. James Caudill American Gem Society Advanced Instruments Paper 060668R received Aug. 28, 2006; revised manuscript received Feb. 16, 8881 West Sahara Avenue 2007; accepted for publication Apr. 10, 2007; published online Oct. 1, 2007. Las Vegas, Nevada 89117 Peter Yantzer American Gem Society Laboratories 8917 West Sahara Avenue Las Vegas, Nevada 89117 1 Introduction are refracted out of the stone.
    [Show full text]
  • Maryland Historical Magazine, 1980, Volume 75, Issue No. 4
    Maryland •listorical Magazine ublished Quarterly by The Museum and Library of Maryland History The Maryland Historical Society Winter 1980 THE MARYLAND HISTORICAL SOCIETY OFFICERS J. Fife Symington, Jr., Chairman* Robert G. Merrick, Sr., Honorary Chairman* Leonard C. Crewe, Jr., Vice Chairman* Frank H. Weller, Jr., President* J. Dorsey Brown, III, Vice President* Stuart S. Janney, III, Secretary* Mrs. Charles W. Cole, Jr., Vice President* John G. Evans, Treasurer* E. Phillips Hathaway, Vice President* J. Frederick Motz, Counsel* William C. Whitridge, Vice President* Samuel Hopkins, Past President* 'The officers listed above constitute the Society's Executive Committee. BOARD OF TRUSTEES H. Furlong Baldwin Richard R. Kline Frederick Co. Mrs. Emory J. Barber St. Mary's Co. Mrs. Frederick W. Lafferty Gary Black, Jr. John S. Lalley James R. Herbert Boone {Honorary) Charles D. Lyon Washington Co. Thomas W. Burdette Calvert C. McCabe, Jr. Philip Carroll Howard Co. Robert G. Merrick, Jr. Mrs. James Frederick Colwill Michael Middleton Charles Co. Owen Daly, II J. Jefferson Miller, II Donald L. DeVries W. Griffin Morrel Emory Dobson Caroline Co. Richard P. Moran Montgomery Co. Deborah B. English Thomas S. Nichols Charles O. Fisher Carroll Co. Addison V. Pinkney Mrs. Jacob France {Honorary) J. Hurst Purnell, Jr. Kent Co. Louis L. Goldstein Culvert Co. George M. Radcliffe Anne L. Gormer Allegany Co. Adrian P. Reed Queen Anne's Co. Kingdon Gould, Jr. Howard Co. Richard C. Riggs, Jr. William Grant Garrett Co. David Rogers Wicomico Co. Benjamin H. Griswold, III Terry M. Rubenstein R. Patrick Hayman Somerset Co. John D. Schapiro Louis G. Hecht Jacques T.
    [Show full text]