DOCSLIB.ORG

Winter 2005 Gems & Gemology

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Winter 2005 Gems & Gemology G EMS & G VOLUME XLI WINTER 2005 EMOLOGY W INTER 2005 P AGES 295–388 Dr. Edward J. Gübelin V OLUME (1913–2005) 41 N O. 4 THE QUARTERLY JOURNAL OF THE GEMOLOGICAL INSTITUTE OF AMERICA ® Winter 2005 VOLUME 41, NO. 4 EDITORIAL _____________ 295 One Hundred Issues and Counting... Alice S. Keller 297 LETTERS ________ FEATURE ARTICLES _____________ 298 A Gemological Pioneer: Dr. Edward J. Gübelin Robert E. Kane, Edward W. Boehm, Stuart D. Overlin, Dona M. Dirlam, John I. Koivula, and Christopher P. Smith pg. 299 Examines the prolific career and groundbreaking contributions of Swiss gemologist Dr. Edward J. Gübelin (1913–2005). 328 Characterization of the New Malossi Hydrothermal Synthetic Emerald Ilaria Adamo, Alessandro Pavese, Loredana Prosperi, Valeria Diella, Marco Merlini, Mauro Gemmi, and David Ajò Reports on a hydrothermally grown synthetic emerald manufactured since 2003 in the Czech Republic. Includes the distinctive features that can be used to separate this material from natural and other synthetic emeralds. pg. 337 REGULAR FEATURES _____________________ 340 Lab Notes Yellow CZ imitating cape diamonds • Orange diamonds, treated by multiple processes • Pink diamonds with a temporary color change • Unusually large novelty-cut diamond • Small synthetic diamonds • Diaspore “vein” in sapphire • Unusual pearl from South America • Unusually small natural-color black cultured pearls • Identification of turquoise with diffuse reflectance IR spectroscopy 350 Gem News International Ornamental blueschist from northern Italy • Emerald phantom crystal • Unusual trapiche emerald earrings • Large greenish yellow grossular from Africa • Opal triplet resembling an eye • Green orthoclase feldspar from pg. 340 Vietnam • New discoveries of painite in Myanmar • Gem plagioclase reported- ly from Tibet • Spinel from southern China • Update on tourmaline from Mt. Mica, Maine • Update on Cu- and Mn-bearing tourmaline from Mozambique • Lizard in amber? • CZ as rough sapphire imitation • Barium-rich glass sold as diamond rough • “Color-change” glass update • Conference reports 370 Book Reviews 373 Gemological Abstracts 381 2005 Index 388 The Last Page: The G&G Digital Archives, 1934–1980 pg. 362 ® EDITORIAL Editor-in-Chief Editor Editors, Lab Notes STAFF Alice S. Keller Brendan M. Laurs Thomas M. Moses and [email protected] The Robert Mouawad Campus Shane F. McClure Publisher 5345 Armada Drive Editor, Gem News International William E. Boyajian Carlsbad, CA 92008 (760) 603-4503 Brendan M. Laurs Managing Editor [email protected] Thomas W. Overton Editors, Book Reviews Associate Editor [email protected] Susan B. Johnson, Stuart Overlin Jana E. Miyahira-Smith, and Technical Editor [email protected] Carol M. Stockton Stuart Overlin Circulation Coordinator Contributing Editor Debbie Ortiz Editor, Gemological Abstracts James E. Shigley (760) 603-4000, ext. 7142 A. A. Levinson* [email protected] PRODUCTION Art Director Production Assistant Web Site: STAFF Karen Myers Allison DeLong www.gia.edu EDITORIAL Shigeru Akamatsu A. J. A. (Bram) Janse George Rossman REVIEW BOARD Tokyo, Japan Perth, Australia Pasadena, California Alan T. Collins Alan Jobbins Kenneth Scarratt London, United Kingdom Caterham, United Kingdom Bangkok, Thailand G. Robert Crowningshield Mary L. Johnson James E. Shigley New York, New York Carlsbad, California Carlsbad, California John Emmett Anthony R. Kampf Christopher P. Smith Brush Prairie, Washington Los Angeles, California New York, New York Emmanuel Fritsch Robert E. Kane Christopher M. Welbourn Nantes, France Helena, Montana Reading, United Kingdom Henry A. Hänni Thomas M. Moses Basel, Switzerland New York, New York SUBSCRIPTIONS Subscriptions to addresses in the U.S. are priced as follows: $74.95 for one year (4 issues), $194.95 for three years (12 issues). Subscriptions sent elsewhere are $85.00 for one year, $225.00 for three years. Canadian subscribers should add GST. Special rates are available for GIA Alumni Association members and current GIA students. One year: $64.95 to addresses in the U.S., $75.00 elsewhere; three years: $179.95 to addresses in the U.S., $210.00 elsewhere. Please have your student or Alumni number ready when ordering. Go to www.gia.edu or contact the Circulation Coordinator. Single copies of this issue may be purchased for $19.00 in the U.S., $22.00 elsewhere. Discounts are given for bulk orders of 10 or more of any one issue. A limited number of back issues are also available for purchase. Please address all inquiries regarding subscriptions and single copy or back issue purchases to the Circulation Coordinator (see above) or visit www.gia.edu. To obtain a Japanese translation of Gems & Gemology, contact GIA Japan, Okachimachi Cy Bldg., 5-15-14 Ueno, Taitoku, Tokyo 110, Japan. Our Canadian goods and service registration number is 126142892RT. ANUSCRIPT Gems & Gemology welcomes the submission of articles on all aspects of the field. Please see the Guidelines for Authors M on our Web site, or contact the Managing Editor. Letters on articles published in Gems & Gemology are also welcome. SUBMISSIONS Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limits of U.S. copyright COPYRIGHT law for private use of patrons. Instructors are permitted to photocopy isolated articles for noncommercial classroom use with- out fee. Copying of the photographs by any means other than traditional photocopying techniques (Xerox, etc.) is prohibited AND REPRINT without the express permission of the photographer (where listed) or author of the article in which the photo appears (where PERMISSIONS no photographer is listed). For other copying, reprint, or republication permission, please contact the Managing Editor. Gems & Gemology is published quarterly by the Gemological Institute of America, a nonprofit educational organization for the jewelry industry, The Robert Mouawad Campus, 5345 Armada Drive, Carlsbad, CA 92008. Postmaster: Return undeliverable copies of Gems & Gemology to The Robert Mouawad Campus, 5345 Armada Drive, Carlsbad, CA 92008. Any opinions expressed in signed articles are understood to be the opinions of the authors and not of the publisher. ABOUT The work of Swiss gemologist Dr. Edward J. Gübelin (1913–2005) forever changed the study of gems. Best known for his research in the area of gemstone inclusions, Dr. Gübelin wrote extensively on virtually every aspect of gemology. He was also THE COVER an innovator in gem-testing instruments, an influential educator, and a global ambassador of gemology. Accompanying this picture of Dr. Gübelin at work in the laboratory are three photomicrographs from his Photoatlas of Gemstone Inclusions (1986, with John I. Koivula). Top to bottom: An inclusion of muscovite in aquamarine from Pakistan (magnified 20×), a pair of scorpions in Dominican amber (magnified 35×), and devitrite inclusions in green glass (magnified 50×). Photo courtesy of Edward W. Boehm; photomicrographs used with permission from Opinion Verlag, Basel, Switzerland. Color separations for Gems & Gemology are by Pacific PreMedia, Carlsbad, California. Printing is by Allen Press, Lawrence, Kansas. © 2005 Gemological Institute of America All rights reserved. ISSN 0016-626X inter 2005 marks the 100th issue of the “new” The Gemological Gems & Gemology, which was introduced in Abstracts section W 1981 with a full peer-review process, new sec- has been critical in tions, and a radical redesign from the smaller format that had exposing our readers defined the journal for more than 45 years. Over the last to developments in quarter century, the relaunched G&G has witnessed a virtual other publications revolution in the science of gemology. and scientific disci- plines, while our Book In the early 1980s, heating of rubies and sapphires and “oil- Reviews have kept the ing” of emeralds were the most prevalent treatments, but of G&G audience up to relatively little concern to the trade. Over the next two date on must-haves (and decades, less-identifiable treatment methods such as irradia- must-nots) for the contem- tion and new processes such as surface diffusion had a porary gemological library. greater impact in the market. More recently, the use of differ- ent emerald fillers, of lead-glass fillers in rubies, and the dif- Radical advances in computer fusion of light elements such as beryllium into corundum capability and access have aided many have raised the bar on the technology being used to treat of the technical developments in gemology colored gems—and to identify those treatments. At the same over the last 25 years, and the rapid expansion of the Internet time, the onset of new and better synthetics has made virtu- has provided new opportunities for communication that go far ally every gem material suspect. beyond the printed page. In keeping with these breakthroughs, I am pleased to announce that beginning in early 2006, every Also in the early 1980s, there were virtually no treatments for issue of Gems & Gemology from 1934 to the present will be colorless diamonds and very few (mainly irradiation/annealing accessible online at www.gia.edu. The 1934–1980 issues will and coating) for their fancy-colored counterparts. With the be available free of charge (see “The Last Page” on p. 388 for advent of fracture filling in the late 1980s and high more), while there will be a small charge for the issues since pressure/high temperature treatment in the late 1990s, dia- 1981. Because it is impossible to ensure the accuracy of the mantaires were rocked by the realization that they, too, must color reproduction on a computer monitor, we strongly rec- rely on gemological research to protect the integrity of their ommend that readers continue to use the printed version as products. This was reinforced by developments in synthetic reference for color-critical images. diamonds: Whereas less than a dozen faceted synthetic diamonds were even known in the early 1980s, today fancy- As a final note, it is particularly appropriate that this 100th colored synthetic diamonds are commercially available in the issue leads off with a tribute to the late Dr. Edward J. Gübelin, marketplace.
Load more

Recommended publications
  • Watch and Clock Makers
    Records Service Records Indexes Watch and Clock Makers This index contains the names; locations and type of watch and clock makers. www.worcestershire.gov.uk/records Complied by Francis Buckley, F.S.A. and George B. Buckley, M.C. from old newspapers and directories. Supplied by Worcester City Museum. January 1984 Surname First Name Established Place Watch/Clockmaker Newspaper Date Reason Other Information Bagnell Before 1770 Dudley Watchmaker Birmingham Gazette 26.02.70 Lost Watch Beavington William 1795 Stourbridge Watchmaker Universal British Directory 1795 Not mentioned Bowler James 1772 Stourbridge Clockmaker Birmingham Gazette 5.10.72 Advertised for John Chance his runaway apprentice Bradley Worcester Not mentioned A well known family of goldsmiths and horologists. An early 18th century watch marked "Bradley, Worcester" is in a Manchester collection. Bradley Samuel 1749-1761 Worcester Watchmaker & Goldsmith Weekly Worcester Journal 27.7.49 - 13.9.50 Bankrupt Berrows Worcester Journal 31.12.61 & 21.2.60 Not mentioned Birmingham Gazette London 6.4.55 Lost watches Evening Post 4.9.53 Not mentioned Birmingham Gazette 18.12.49, 21.1.51 & Not mentioned Bradley Mrs. 1774-1783 Worcester Goldsmith Birmingham Gazette 15.08.74 & 1.9.83 Died 23rd August 1783 High Street Possibly identical with (or related to) Samuel Bradley Bradley Joseph 1749 Worcester Watchmaker Weekly Worcester Journal 2.2.49 Not mentioned Brown Joseph 1767-1796 Worcester Clockmaker & Watchmaker & Berrows Worcester Journal 18.6.67 Mentioned at St. John's end of Severn Bridge Goldsmith Directories 1790 Not mentioned . 1792-96 Newport street Berrows Worcester Journal 27.5.71 St.
    [Show full text]
  • Painite, Cazrblllro,Rl: Its Crystal Structure and Relation To
    American Mineralogist, Volume 61, pages 88-94, 1976 Painite, CaZrBlLlrO,rl: Its crystalstructure and relationto jeremejevite,Bu[[rAl6(OH)sO1r], and fluoborite, Br[Mgr(F, OH)rOr] Plur- BRre,uMooRE r.No TnreHnnu AnerI Department of the Geophysical Sciences, The Uniuersity of Chicago Chicago, Illinois 60637 Abstract Painite-CazrB[Al,O,s], hexagonalP6s, a :8.715(2), c : 8.472(2)A,Z : 2-possessesa rigid and dense [AlrO,r]'- octahedralframework, topologically identical to those found in jeremejevite, B'[IBAI6(OH)aO,,] and fluoborite, B,[Mg,(F,OH),O,]. R : 0.071 for l6l8 independent reflections. The octahedralframework is linked to [BOr]3 trianglesand [ZrOu]8-trigonal prismsatlf z and a largepipe at 0 0 z is cloggedwith compressed[CaO"]'0- octahedra. Average interatomic distancesareCa-O=2.398,2r-O:2.126,8-O:1.380,A1(l)-O: l.9l5,Al(2)-O: 1.918, and Al(3)-O : l.9l4A. The octahedral framework in painite, resistantto attack by acids and bases,suggests a highly refractoryphase and the possibilityof other equally resistantcompounds, hypothetical examplesbeing NaNbs+B[Alrors] and llUutB[Al"O,"]. ln the latter, thepipewould be lree from obstructions. Introduction Three-dimensionalsingle-crystal X-ray diffraction intensitiesabout the a2-rotation axis were collected Painite is a curious mineral species,first reported on a PnILnrn semi-automateddiffractometer with by Claringbull, Hey and Payne(1957) from the ruby graphite monochromatized MoKa, (tr : 0.70926A) minesof Mogok, Burma. It was found as a garnet-red radiation. With 2d-^* : 69.5", data were gathered 1.7 gram singlehexagonal crystal of hardness8. They through the k -- 0- to ll-levels.
    [Show full text]
  • Magazine PATEK PHILIPPE
    A TUFTS COMMUNICATIONS FINE JEWELRY PUBLICATION C.D.PEACOCK MAGAZINE • OVER 180 YEARS IN CHICAGO AUTUMN/HOLIDAY 2018 ISSUE 3 C.D.Peacockmagazine ROLEX Philanthropy CARTIER Classic Style MIKIMOTO A Lustrous Milestone World Timer by PATEK PHILIPPE HEARTS ON FIRE Put a ring on it FALL 2018 • ISSUE 3 Since 1837, C.D.Peacock has been the Chicago area’s premier source of fine diamonds. At C.D.Peacock we believe that a Scustomer, like a fine diamond, should be forever. Our position as a prominent International jeweler enables our access to the finest diamonds the world has to offer at the best value. We’ve based our reputation on it for over a century. Warmest greetings from all of us at C.D.Peacock. Each year we look forward to the opportunity to share with you our vision and passion that is translated into our exquisite jewelry. In this issue, you will find 2019 trends, profiles on a few of our favorite designers and Swiss watch brands, exotic travel destinations, and much more. While we strive to always stay ahead of the curve to bring you the latest jewelry designs and Wwatch innovations from around the world, at the heart of it all, we are still a family-owned business. At C.D.Peacock we believe in the traditional values of honesty, integrity, customer service, and philanthropy. We still hand-select each item we offer in our stores and have earned a reputation of tremendous international respect within the industry. This holiday season and beyond, we welcome the opportunity to help you select the perfect gift to honor those who give special meaning to your life.
    [Show full text]
  • Thomas, R., Rericha, A., Pohl, WL, Davidson, P
    Originally published as: Thomas, R., Rericha, A., Pohl, W. L., Davidson, P. (2018): Genetic significance of the 867 cm−1 out-of- plane Raman mode in graphite associated with V-bearing green grossular. - Mineralogy and Petrology, 112, 5, pp. 633—645. DOI: http://doi.org/10.1007/s00710-018-0563-1 1 Genetic significance of the 867 cm-1 out-of-plane Raman mode in graphite associated with V-bearing green grossular Rainer Thomasa Adolf Rerichab Walter L. Pohlc Paul Davidsond Paul Davidson [email protected] 0000-0002-6129-0748 a Helmholtz-Centre Potsdam, German Research Centre for Geoscience – GFZ, Section 4.3. Chemistry and Physics of Earth Materials, Telegrafenberg, D-14473 Potsdam, Germany b Alemannenstr. 4a, D-14612 Falkensee, Germany c Austrian Academy of Sciences, Dr. Ignaz Seipel-Platz 2, 1010 Vienna, Austria d ARC Centre of Excellence in Ore Deposits, University of Tasmania, Hobart 7001, Australia Keywords: Tsavorite Green V-grossular Graphite Raman scattering Fluid and melt inclusions Sulfur 2 Abstract SE Kenya is the world’s largest producer of green vanadium grossular gemstones (tsavorite). Samples from one of the mines near Mwatate, and of occurrences in Tanzania yielded remarkable new insights into the genesis of tsavorite. Graphite is intimately associated with V-grossular and is one of the keys to understanding its origin. In the course of this study we found five different types of graphite. Surprisingly, in one graphite type the “Raman- forbidden” and IR-active 867 cm-1 band was observed. In this communication, we attempt to find an explanation for this unusual phenomenon.
    [Show full text]
  • Fine Watches & Wristwatches
    Fine Watches & Wristwatches Including a Private English Collection Tuesday 11 June 2013 at 1pm New Bond Street, London Fine Watches & Wristwatches including a Private English Collection Tuesday 11 June 2013 at 1pm New Bond Street, London Bonhams Enquiries Illustrations Important Notice 101 New Bond Street Paul Maudsley Front cover: Lot 356 A surcharge of 2% is applicable London W1S 1SR +44 (0) 20 7447 7412 Back cover: Lot 36 (detail) when using Mastercard, Visa and bonhams.com Inside front cover: Lot 308 overseas debit cards. Kate Lacey Inside back cover: Lot 318 Viewing +44 (0) 20 7468 8301 The following symbol is used to denote that VAT is due on Sunday 9 June 11am to 3pm Sophia Guy-White Sale Number: 20747 the hammer price and buyer’s Monday 10 June 9am to 4.30pm +44 (0) 20 7447 7413 premium Tuesday 11 June 9am to 11am +44 (0) 20 7468 8370 fax Catalogue: £15 † VAT 20% on hammer price Highlight Viewing [email protected] and buyer’s premium Catalogue Subscriptions: 22 - 25 May +44 (0) 1666 502 200 Island Shangri-La Hotel Shipping * VAT on imported items at a preferential rate of 5% on Hong Kong For information and estimates hammer price and the prevailing on domestic and international rate on buyer’s premium Bids shipping please contact the Important notice +44 (0) 20 7447 7448 Department on: regarding importation Ω VAT on imported items at +44 (0) 20 7447 7401 fax +44 (0) 20 7 447 7413 into the United States 20% on hammer price and the To bid via the internet please visit [email protected] of Corum, Franck prevailing rate on buyer’s premium bonhams.com Muller, Piaget and Customer Services Rolex Watches.
    [Show full text]
  • Gem Wealth of Tanzania GEMS & GEMOLOGY Summer 1992 Fipe 1
    By Dona M.Dirlarn, Elise B. Misiorowski, Rosemaiy Tozer, Karen B. Stark, and Allen M.Bassett The East African nation of Tanzania has he United Republic of Tanzania, the largest of the East great gem wealth. First known by Western- 1African countries, is composed of mainland Tanzania and ers for its diamonds, Tanzania emerged in the island of Zanzibar. 1t is regarded by many as the birthplace the 1960s as a producer of a great variety of of the earliest ancestors of Homo sapiens. To the gem indus- other gems such as tanzanite, ruby, fancy- try, however, Tanzania is one of the most promising fron- colored sapphire, garnet, and tourmaline; to date, more than 50 gem species and vari- tiers, with 50 gem species and varieties identified, to date, eties have been produced. As the 1990s from more than 200 occurrences. begin, De Beers has reinstated diamond "Modem" mining started in the gold fields of Tanzania in exploration in Tanzania, new gem materials the late 1890s (Ngunangwa, 19821, but modem diamond min- such as transparent green zoisite have ing did not start until 1925, and nearly all mining of colored appeared on the market, and there is stones has taken place since 1950. Even so, only a few of the increasing interest in Tanzania's lesser- gem materials identified have been exploited to any significant known gems such as scapolite, spinel, and extent: diamond, ruby, sapphire, purplish blue zoisite (tan- zircon. This overview describes the main zanite; figure l),and green grossular [tsavorite)and other gar- gems and gem resources of Tanzania, and nets.
    [Show full text]
  • TUCSON 2018 Spinel—In Pink and Lavender Hues—In Suites and Sets As Customers Found the Scarcity and High Prices of Red Spinel Prohibitive
    Contributing Editors Emmanuel Fritsch, University of Nantes, CNRS, Team 6502, Institut des Matériaux Jean Rouxel (IMN), Nantes, France (fritsch@cnrs- imn.fr) Gagan Choudhary, Gem Testing Laboratory, Jaipur, India ([email protected]) Christopher M. Breeding, GIA, Carlsbad ([email protected]) manite. Many dealers posted strong sales of pastel-colored spinel—in pink and lavender hues—in suites and sets as TUCSON 2018 customers found the scarcity and high prices of red spinel prohibitive. In a similar vein, Margit Thorndal of Madagas- Every February the gem and mineral world descends on car Imports reported strong demand for purple-lavender Tucson, transforming the downtown convention center spinel and purple sapphire from Madagascar, as well as teal and a great many of the city’s hotels into a fascinating col- hues of unheated Montana sapphire. lage of traders bearing goods from all over the planet (fig- We noted that electric blues, teals, hot pinks, hot yel- ures 1 and 2). low greens, and pastel-colored gems were quite popular. Many of the exhibitors we spoke with described 2018 Bill Larson of Pala International pointed to this trend and as the strongest year since 2008. Although traffic wasn’t showed us a number of spectacular examples from his in- especially heavy at the AGTA and GJX shows, most deal- ventory. Fine blue zircon from Cambodia was prominent, ers there enjoyed brisk sales and healthy demand for high- as was attractive sphene from Zimbabwe and Madagascar. quality goods. Some of the same trends from last year were Dave Bindra of B&B Fine Gems said his company was evident.
    [Show full text]
  • New Mineral Names*
    American Mineralogist, Volume 73, pages 1492-1499. 1988 NEW MINERAL NAMES* JOHN L. JAMBOR CANMET, 555 Booth Street, Ottawa, Ontario KIA OGI, Canada ERNST A. J. BURKE lnstituut voor Aardwetenschappen, Vrije Universitiete, De Boelelaan 1085, 1081 HV, Amsterdam, Netherlands T. SCOTT ERCIT, JOEL D. GRICE National Museum of Natural Sciences, Ottawa, Ontario KIA OM8, Canada Acuminite* prismatic to acicular crystals that are up to 10 mm long and 0.5 H. Pauly, O.Y. Petersen (1987) Acuminite, a new Sr-fluoride mm in diameter, elongate and striated [001], rhombic to hex- from Ivigtut, South Greenland. Neues Jahrb. Mineral. Mon., agonal in cross section, showing {l00} and {l10}. Perfect {100} 502-514. cleavage, conchoidal fracture, vitreous luster, H = 4, Dm'.. = 2.40(5) glcm3 (pycnometer), Dcale= 2.380 glcm3 for the ideal Wet-chemical analysis gave Li 0.0026, Ca 0.0185, Sr 37.04, formula, and Z = 4. Optically biaxial positive, a = 1.5328(4), (3 Al 11.86, F 33.52, OH (calc. from anion deficit) 6.82, H20 (calc. = 1.5340(4), 1.5378(4), 2 Vmoa,= 57(2)°, 2 Vcale= 59°; weak assuming 1 H20 in the formula) 7.80, sum 97.06 wt%, corre- 'Y = dispersion, r < v; Z = b, Y A c = -10°. X-ray structural study sponding to Sro98AIl.o2F.o7(OH)o.93H20. The mineral occurs as indicated monoclinic symmetry, space group C21c, a = 18.830(2), aggregates of crystals shaped like spear points and about I mm b= I 1.517(2), c= 5.190(I)A,{3 = 100.86(1)°. A Guinierpowder long.
    [Show full text]
  • New Data on Painite
    MINERALOGICAL MAGAZINE, JUNE 1986, VOL. 50, PP. 267 70 New data on painite JAMES E. SHIGLEY Research Department, Gemological Institute of America, 1660 Stewart Street, Santa Monica, California 90404 ANTHONY R. KAMPF Mineralogy Section, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, California 90007 AND GEORGE R. ROSSMAN Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA ABSTRACT. A crystal of painite discovered in 1979 in a structure and reported its space group as P63. parcel of rough gem spinel from Burma represents the Powder diffraction data for the 1979 crystal were third known crystal of the species. This crystal is similar to obtained using a Debye-Scherrer camera and the type crystal in most respects. Chemical analyses of Cu-Kcz radiation. They confirmed its identity and both the new crystal and the type crystal confirmed the least squares refinement provided the cell constants essential constituents reported by Moore and Araki (1976) and showed in addition the presence of trace given in Table I. These are slightly larger than the amounts of Fe, Cr, V, Ti, Na, and Hf. Optical absorption cell constants determined by Claringbull et al. spectra suggest that the red colour of painite is caused (1957) and Moore and Araki (1976) for the type principally by Cr 3§ and V3 +. crystal. KEYWORDS: painite, new data, colour, Mogok, Burma. PAINITE is one of the rarest minerals, known Table I. Physical properties and unit previously in only two crystals. This paper cell parameters of painite describes a third known crystal of the species, and Type painite 1 1979 painite provides additional data for the type specimen.
    [Show full text]
  • Making Gravers by William R
    WEAR YOUR SAFETY GLASSES FORESIGHT IS BETTER THAN NO SIGHT READ INSTRUCTIONS BEFORE OPERATING Making Gravers By William R. Smith William R. Smith is well known in the field of clock making. He has recently designed a T-rest for the Sherline lathe that makes it possible to hand turn parts using a tool called a “Graver”, which is a common technique in watch- and clock making. This technique is also used in instrument making and modelmaking for turning special shapes like ball ends without having to grind a specially shaped cutter for the job. Mr. Smith’s credentials include a degree in mechanical engineering as well as FBHI (Fellow, British Horological Institute), FNAWCC (Fellow, National Association of Watch and Clock Collectors), CMC (Certified Master Clockmaker), CMW (Certified Master Watchmaker) and CMEW (Certified Master Electronic Watchmaker.). He has published several books and videos on clock making which will be of interest to anyone wishing to learn more about hand turning techniques or about making clocks. CAUTION: Use gravers carefully. Hold work materials with a and ruin them, all sharpening must be done by hand on a collet. Do not use gravers with a 3-jaw or 4-jaw chuck. A graver bench stone or a special wet grinder. which is inadvertently pushed into a spinning chuck jaw can be The gravers to be described here do not suffer this problem. flung from your hands. See T-rest instructions for further cautions Though harder than high carbon steel gravers and slightly and turning techniques. more prone to chip, they can be reshaped at the bench grinder Carbide Gravers quickly and without harm provided one does not let them I have often been asked to explain why I seem so unimpressed go red or cool them in water during the shaping process.
    [Show full text]
  • POUDRETTEITE, Knarb3si12o3e, a NEW MEMBER of the OSUMILITE GROUP from MONT SAINT-HILAIRE, OUEBEC, and ITS CRVSTAL STRUCTURE Assr
    Canadian Mineralogist Vol. 25, pp.763-166(1987) POUDRETTEITE,KNarB3Si12O3e, A NEW MEMBEROF THE OSUMILITEGROUP FROM MONT SAINT-HILAIRE,OUEBEC, AND ITS CRVSTALSTRUCTURE JOEL D. GRICE, T. SCOTT ERCIT AND JERRY VAN VELTHUIZEN Mineral SciencesDivision, National Museumof Natural Sciences,Ottawa, Ontario KIA 0M8 PETE J. DUNN Departmentof Mineral Sciences,Smithsonian Institution, Washington,D.C, 20560,U,S.A. Assrnact positionC d coordinanceXII, le sodium,la position,4d unecoordinance VI, le bore,la position72 ir coordinance Poudretteiteis a newmineral species from the Poudrette IV, le silicium,la position71 i coordinanceIV, etla posi- quarry, Mont Saint-Hilaire,Quebec. It occursin a marble tion B estvacante. xenolith includedin nephelinesyenite, associated with pec- tolite, apophyllite, quartz and minor aegirine.It forms clear, Mots-clds: poudrettdite, nouvelle espbce min6rale, groupe colorlessto very pale pink, equidimensional,subhedral del'osumilite, mont Saint-Hilaire, borosilicate, affi ne. prismsup to 5 mm. It is brittle, H about 5, with a splin- mentde Ia structure. tery fracture;Dmetr. 2.51(l) g/cml, D"6".2.53 g/cm3. Uniaxialpositive, co 1.516(l), e 1.532(l).It is-hexagonal, spacegroup P6/ mcc, a I 0.239(l), c 13.485(3)A and,Z : 2. INTRoDUcTIoN The strongestten X-ray-diffractionlines in the powderpat- tern [d in A(r\(hkDl are: 6.74(30)(002),5.13 (100)(110), The optical and physical propertiesof members 4.07(30)(r 12), 3.70(30)(202), 3.3 6e(30)(004), 3.253 ( I 00) of the osumilite group are similar to those of com- (2r r), 2.9s6(40)(3 00), 2.8 I 5(60)(I I 4), 2.686(50)(213,204) mon mineralssuch as quartz and cordierite;for this and 2.013(30)(321).An analysisby electron microprobe reason, they are probably generally overlooked.
    [Show full text]
  • Gem Quality Johachidolite: Occurrence, Chemical Composition and Crystal Structure
    No.5 November 2007 GEM QUALITY JOHACHIDOLITE: OCCURRENCE, CHEMICAL COMPOSITION AND CRYSTAL STRUCTURE MESSAGE Editor Message from the Editor’s Desk Dr. A. Peretti, FGG, FGA, EurGeol GRS Gemresearch Swisslab AG, P.O.Box 4028, The continuous research on new gem occurrences 6002 Lucerne, Switzerland and new gemstones is a very important aspect of [email protected] the activities of a modern gemological laboratory. With the description of a revised crystal structure Previous Journals of painite in our previous publication and the description of the new gem mineral pezzottaite, GRS has invested much in this tradition. It has featured its discoveries in two issues of Contribution to Gemology No. 2 and No. 3 and published the detailed results in American Mineralogist and Mineralogical Record (see literature). Research institutions all over the world, some of them considered the most prestigious in this field of research such as Caltech University, have made links to the online version of our journal at www.gemresearch.ch, particularly suitable for students to appreciate our extensive use of illustrations. Every day several thousand visitors search our website from more than 15 countries, confirming the interest in rare collector gems in the gem community and the public. It took GRS and its collaborating scientific partners in Switzerland almost two years of intensive research to make another important discovery of corresponding caliber. Again, it is a discovery in the field of new gem occurrences and new important data on mineral structures and mineral chemistry. This time the news is not coming from new mines in Madagascar but from the famous valley of Mogok in Burma, renowned for its fabulous rubies and sapphires.
    [Show full text]