DOCSLIB.ORG

Volume 23 / No. 8 / 1993

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Volume 23 / No. 8 / 1993 Volume 23 No. 8. October 1993 The Journal of Gemmology THE GEMMOLOGICAL ASSOCIATION AND GEM TESTING LABORATORY OF GREAT BRITAIN OFFICERS AND COUNCIL Past Presidents: Sir Henry Miers, MA, D.Sc., FRS Sir William Bragg, OM, KBE, FRS Dr. G.F. Herbert Smith, CBE, MA, D.Sc. Sir Lawrence Bragg, CH, OBE, MC, B.Sc, FRS Sir Frank Claringbull, Ph.D., F.Inst.P., FGS Vice-Presidents : R. K. Mitchell, FGA A.E. Farn, FGA D.G. Kent, FGA E. M. Bruton, FGA, DGA Council of Management CR. Cavey, FGA TJ. Davidson, FGA N.W. Deeks, FGA, DGA I. Thomson, FGA V.P. Watson, FGA, DGA R.R. Harding, B.Sc., D.Phil., FGA, C. Geol. Members' Council A. J. Allnutt, M.Sc, G.H. Jones, B.Sc, Ph.D., P. G. Read, C.Eng., Ph.D., FGA FGA MIEE, MIERE, FGA, DGA P. J. E. Daly, B.Sc, FGA J. Kessler I. Roberts, FGA P. Dwyer-Hickey, FGA, G. Monnickendam R. Shepherd DGA L. Music R. Velden R. Fuller, FGA, DGA J.B. Nelson, Ph.D., FGS, D. Warren B. Jackson, FGA F. Inst. P., C.Phys., FGA CH. Winter, FGA, DGA Branch Chairmen: Midlands Branch: D.M. Larcher, FBHI, FGA, DGA North-West Branch: I. Knight, FGA, DGA Examiners: A. J. Allnutt, M.Sc, Ph.D., FGA G. H. Jones, B.Sc, Ph.D., FGA L. Bartlett, B.Sc, M.Phil., FGA, DGA D. G. Kent, FGA E. M. Bruton, FGA, DGA R. D. Ross, B.Sc, FGA C R. Cavey, FGA P. Sadler, B.Sc, FGS, FGA, DGA S. Coelho, B.Sc, FGA, DGA E. Stern, FGA, DGA A.T. Collins, B.Sc, Ph.D Prof. I.Sunagawa, D.Sc. B. Jackson, FGA C Woodward, B.Sc, FGA, DGA E. A. Jobbins, B.Sc, C Eng., FIMM, FGA Editor: E. A. Jobbins, B.Sc, C.Eng., FIMM, FGA Editorial Assistant: Mary A. Burland The Gemmological Association and Gem Testing Laboratory of Great Britain 27 Greville Street, London EC1N 8SU Telephone: 071-404 3334 Fax: 071-404 8843 TheJournal of Gemmology VOLUME 23 NUMBER EIGHT OCTOBER 1993 Cover Picture Brooch set with pink Argyle diamonds, maximum width approx 7cm; 1068 pink diamonds and 160 white diamonds weighing a total of 16.31 ct and 3.45 ct respectively. See 'Gemmological properties of Type la diamonds with an unusually high hydrogen content' pp.451-60. Photo courtesy of Graff, 6-7 New Bond Street, London Wl. ISSN: 0022-1252 © Copyright the Gemmological Association ISSN: 0022-1252 J. Gemm, 1993,23,8 450 STUDENT STARTER SET AN IDEAL STARTER SET FOR ALL STUDENTS OF GEMMOLOGY THIS SET INCLUDES: 18mm 1 Ox Loupe (ovailable in chrome or matt black finish) Medium Stone Tongs Chelsea Colour Filter OPL Spectroscope SPECIAL INTRODUCTORY PRICE £60.00 plus VAT, postage and packing Normal Retail Price £66.95 plus VAT, postage and packing GAGTL members receive an additional 10% discount on the Special IntroducTory Price To order your set please use the order form following p.496 (Please quote your membership number when placing an order) Gemmological Instruments Limited • FIRST FLOOR, 27 GREVILLE STREET, (SAFFRON HILL ENTRANCE), LONDON EC1N 8SU • Tel: 071 404 3334 Fax: 071 404 8843 J. Gemm., 1993, 23, 8 451 Gemmological properties of Type Ia diamonds with an unusually high hydrogen content Emmanuel Fritsch* and Ken Scarratt† *GIA Research, Santa Monica, CA, USA †GIA Gem Trade Laboratory, New York, NY, USA Abstract erties of natural and treated coloured diamonds, One hundred and thirty-nine Type Ia diamonds that we have studied a number of diamonds with showed unusually intense hydrogen-related absorptions unusual characteristics. For example, we recently in the infrared range were studied; they are referred to as reported on a greyish-blue coloration in diamond 'H-rich diamonds' for brevity. We demonstrate that the believed to be caused by hydrogen-related colour various kinds of H-rich diamonds often have a number centres (Fritsch and Scarratt, 1992). The presence of gemmological and physical properties in common, for example a yellow luminescence, certains types of colour of hydrogen in diamond can be detected by a series of sharp absorptions in the infrared region, zoning and clouds of sub-microscopic inclusions. We 1 also report the discovery of several new hydrogen-related especially at 1405 and 3107 cm , which have been absorptions in the infrared and the visible ranges, some known since 1961 and attributed by Charette to giving rise to a violet colour never described before in C-H bonds (Charette, 1961). These two frequen­ coloured diamonds. cies are also known as hcob (1405 cm1), the Key words: Diamond, Hydrogen, Infrared, Colour elementary frequency for the bending motion of centre. the C-H bond, and hcos (3107 cm1) the elemen­ tary frequency for the stretching motion of the Introduction C-H bond. In recent years hydrogen has been recognized as Over the last five years, a number of gem-quality a common impurity in natural Type Ia diamonds diamonds exhibiting strong C-H bands at 3107 (Woods and Collins, 1983), in addition to the cm-1 have become available. For convenience, well-known nitrogen (and possibly boron) impu­ these diamonds are hereafter called 'H-rich dia­ rities. Little is known, however, of the influence monds' but, strictly speaking, they only are that this hydrogen impurity may have on the diamonds with unusually intense hydrogen- optical properties of such diamonds, in particular related infrared absorptions. These diamonds, their colour. In the course of the coloured although they may have different appearances, diamond project, undertaken at GIA Research present a number of gemmological properties in since 1986 in order to better understand the prop- common. The large number of samples we Fig. 1. Four typical H-rich diamonds, ranging in colour from Fig. 2. Greyish-violet 0.88 ct pear-shaped diamond and brown- greyish-yellow (0.28 ct, left), to light brownish-yellow (1.02 yellow 1.20 ct round brilliant-cut, both from the Argyle mine ct, centre) to light grey (0.09 and 0.15 ct, right). Stones in western Australia. They represent typical examples of H- courtesy Davenport Jewelry Company, Dallas, Texas. Photo rich diamonds described in detail in this paper. Stones by Robert Weldon courtesy of Argyle Diamonds. Photo by Robert Weldon © Copyright the Gemmological Association ISSN: 0022-1252 452 J. Gemm., 1993, 23, 8 Fig. 3. The vast majority of 'white' or 'opalescent' diamonds, such as Fig. 5. Brownish colour zones limited by planar borders in a greyish- these three round brilliant-cuts from the Panna mine in India green chameleon diamond. Magnification lOx. ranging from 0.30 to 0.33 ct, are also H-rich diamonds. Photomicrograph J.I. Koivula Stones courtesy Malhotra Inc., New York. Photo by R. Weldon studied (over one hundred) has enabled us to doc­ a Nicolet 60SX FTIR spectrometer at a resolution ument a number of absorptions in the infrared and of 4 cm1 in the range 400-25000 cm1. Use of a visible ranges related to the presence of the hydro­ microbeam chamber allowed for maximum energy gen impurity, some of which had never been output. described before. In particular, some rare hydro­ All samples were selected because they exhibit gen-rich diamonds from Argyle in western an absorption band at 3107 cm1 that is particu­ Australia exhibit a violetish-grey to greyish-violet larly intense, generally comparable or superior in colour never described before in coloured dia­ intensity to the intrinsic two-phonon diamond monds. absorption around 2450 cm1 (Figure 4. We indi­ cate on this figure a position of 3105 cm1, not Materials and methods 3107, because our spectra are done at a resolution The 139 samples examined in this study were of 4 cm'1 only). all faceted gem-quality diamonds, on loan from For this report, we have tentatively distin­ private parties. They represent a wide range of guished four types of H-rich diamonds on the colour with essentially yellow, grey (Figure 1) or basis of their properties: the 'brown to greyish- brown as the main component (for 78 of them), yellow family' (66 samples), the £grey to violet but also bluish-grey to greyish-violet (for 6 of family' (14), white diamonds (8) and finally them), white (also called 'opalescent diamonds' in 'chameleon diamonds' (36). 15 samples could not the trade; 8 samples) and blue and green (47 be classified because the necessary data were not samples). Their geographical origin is generally available for various reasons. We call 'chameleon unknown, as is unfortunately the case with most diamonds' those that typically change reversibly diamonds. However, the bluish-grey to greyish- from a grey-green to a brighter yellow colour when violet stones are all from Argyle, as well as one heated in the flame of an alcohol lamp. Such pho- brown-yellow (Figure 2) and one greenish-yellow tochromic behaviour was formerly described by stone. A series of three white diamonds is from the Raal and Robinson (1982) in treated Type Ia dia­ Panna mine, India (Figure 3). monds and in some natural green diamonds from This sampling includes 31 stones either known the South African gold mines (Raal, 1969). Brief to be treated, or established to be so based on cri­ gemmological reports on chameleon diamond teria explained elsewhere (Fritsch and Shigley, behaviour can be found in Crowningshield (1975) 1989 and 1991). Although most of these treated, and Fryer (1981, 1982). hydrogen-rich stones were essentially green or blue (sample 8; Fritsch and Shigley, 1989), we Gemmological properties documented also' some that were essentially yellow Microscopic, examination (sample 2; ibid.). Sixty-four of the 131 H-rich diamonds that are All data collection was done at GIA Research.
Load more

Recommended publications
  • The Most Important Collection of Period Jewels to Be Offered at Christie's New York
    For Immediate Release 20 March 2008 Contact: Sara Fox +1 212 636 2680 [email protected] THE MOST IMPORTANT COLLECTION OF PERIOD JEWELS TO BE OFFERED AT CHRISTIE’S NEW YORK Rare Jewels and Gemstones: The Eye of a Connoisseur 15 April 2008 New York — Christie’s is honored to announce the most spectacular and comprehensive collection of period jewels from the 17th century through modern day in the April 15th evening sale in New York, Rare Jewels and Gemstones: The Eye of a Connoisseur. With 115 lots, this extraordinary collection expects to realize record prices for historical jewels, iconic emblems of the Art Nouveau and Art Deco periods and also one of the most important pink diamonds ever to be offered for sale at auction. François Curiel, Christie’s Chairman of Jewellery, commented, "When I reflect upon all that I have seen during my 40-year Christie's career, both at auction and privately, this collection strikes me as unparalleled to virtually any other in the world for its provenance, breadth, size and rarity. Never before have I seen assembled together such a great number of quintessential jewels from the 17th and 18th centuries, all the way to the Art Nouveau and Art Deco periods, and into the 21st century. This unique ensemble represents a walk through some of history’s most prominent figures and their jewels." Empress Eugénie’s Brooch Leading the historically prominent works offered in this collection is a sensational antique diamond bow brooch, by François Kramer which was made for Empress Eugénie and later owned by the Astor family of New York (estimate: $4-6 million).
    [Show full text]
  • Vol 7, Issue 4, December 2008
    mag28.qxd 28/11/2008 08:56 Page 1 MAGAZINE OF THE GEOLOGISTS’ ASSOCIATION Volume 7 No. 4 December 2008 Meetings Jan/Feb/March CIRCULAR 977 Besotted by Baltica Festival Dinner Wealden Field Trip Letter to Editor Festival Report Jurassic Churches Part 1 Obituary to Bob Stoneley The PGA Illustrated Festival Field Trip Book Review Mole Valley go to Sea Book Reviews Photographic Competition Mons Porphyrites Rockwatch News winners mag28.qxd 28/11/2008 08:53 Page 2 Magazine of the Geologists’ From the President Association Autumn is proving to be a busy time for the 150150 Volume 7 No.4, 2008 GA! On 31st October, I met with the Local GAGA Groups and Affiliated Societies for the first time as President. We are going through a period of is published by the review so feedback from the groups is very CONTENTS important, particularly when it comes to tackling Geologists’ Association. difficult problems such as boosting membership. Four issues are 3. The Association The meeting was a positive one with excellent suggestions made as to how activities can be produced in the year. 4. GA Meetings Jan/Feb/March advertised and events organised. In the evening, I ISSN 1476-7600 5. Festival Dinner joined around 120 members to celebrate the 6. Festival Report 150th Anniversary of the Association with a Production team: JOHN CROCKER, wonderful Gala Dinner at the Café Royal on Paula Carey, John Cosgrove, 7. The PGA Illustrated Regent Street. Guests were provided with a sou- Vanessa Harley, Bill French 9. Mole Valley go to Sea venir menu from the 1880 GA Dinner, as well as that night's menu adorned with great sketches by Printed by City Print, Milton Keynes 10.
    [Show full text]
  • And of the Sinhalese (Tfecese)
    The Story of the [and of the Sinhalese (tfeCese) Ariesen Ahubudu Translated in to English by Nuwansiri Jayakuru B.A (Hon.) cey A Stamford Lake Publication 2012 First Print 2012 8 Ariesen Ahubudu Translated in to English by Nuwansiri Jayakuru (B.A.Hon) cey. ISBN 978-955-658-313-7 Price: Rs. 350.00 Type Setting by Stamford lake Cover Design by Rex Hamilton Fernando Printed and Published by Stamford Lake (Pvt) Ltd. 366, High Level Road, Pannipitiya, Sri Lanka. Tele/Fax : 011-2846002, 011-4208134 E-mail: [email protected] Web purchasing: www.lakehousebookshop.com INTRODUCTION 'Hela Sada Peheliya' is a book that I began to write giving detailed meanings to Sinhala (Hela) words in the style of a dictionary. My intention is to divide it into a number of Volumes such as 'Hela Derana Vaga' (the story of the land of the Sinhalese-Helese), Hela Avurudu Vaga (the story of the Hela New Year), Hela Gam Nam Vaga (the story of the village names of the Helese), Hela Dev Vaga (the story of the Hela Gods), Hela Bas Vaga (the story of the Hela Language), Rukliya Vaga (the story of the trees and creepers) Sat Vaga (the story of animals), Siruru Vaga (the story of the human body), Do Satara Vaga (the story of Astrology) Keli Vaga (the story of our games) Na Siya Vaga (the story of relationships). Hela Derana Vaga is the first in that series. Since it is bulky in terms of facts and size, I thought of having it published as a separate book.
    [Show full text]
  • Property from the Portland Collection at Christie's In
    For Immediate Release Monday, 8 November 2010 Press Contact: Hannah Schmidt +44 (0) 207 389 2964 [email protected] Matthew Paton +44 (0) 207 389 2965 [email protected] PROPERTY FROM THE PORTLAND COLLECTION AT CHRISTIE’S IN NOVEMBER & DECEMBER Magnificent Jewels, Fabergé, Old Masters and Sculpture The Duchess of Portland in The Combat between Carnival and Lent by Pieter Brueghel II coronation robes, 1902 (Brussels 1564- 1637/8 Antwerp) © gettyimages: Hulton Archive Estimate: £2,000,000–3,000,000 London – Christie’s announce an historic opportunity for connoisseurs around the globe in late November and early December, when a magnificent selection of jewellery, Fabergé, old master paintings and sculpture will be offered from collections of the Dukes of Portland, in a series of auctions in London. 22 lots will be showcased in four auctions over two weeks: Russian Art on Tuesday 29 November; Jewels: The London Sale on Wednesday 1st December; Old Masters & 19th Century Art on Tuesday 7th and 500 Years: Decorative Arts Europe on Thursday 9th. Highlights are led by the re-appearance of The Combat between Carnival and Lent by Pieter Brueghel II (Brussels 1564-1637/8 Antwerp) (estimate: £2,000,000– 3,000,000), illustrated above, a sumptuous antique diamond and natural pearl brooch, with three drops, 1870 (estimate: £500,000-700,000) and an exceptionally rare terracotta bust of John Locke, 1755, by Michael Rysbrack (1694-1770) (estimate: £600,000-900,000). With estimates ranging from £4,000 to £3 million, Property from The Portland Collection is expected to realise in excess of £6 million.
    [Show full text]
  • The Journal of Gemmology Editor: Dr R.R
    he Journa TGemmolog Volume 25 No. 8 October 1997 The Gemmological Association and Gem Testing Laboratory of Great Britain Gemmological Association and Gem Testing Laboratory of Great Britain 27 Greville Street, London Eel N SSU Tel: 0171 404 1134 Fax: 0171 404 8843 e-mail: [email protected] Website: www.gagtl.ac.uklgagtl President: Professor R.A. Howie Vice-Presidents: LM. Bruton, Af'. ram, D.C. Kent, R.K. Mitchell Honorary Fellows: R.A. Howie, R.T. Liddicoat Inr, K. Nassau Honorary Life Members: D.). Callaghan, LA. lobbins, H. Tillander Council of Management: C.R. Cavey, T.]. Davidson, N.W. Decks, R.R. Harding, I. Thomson, V.P. Watson Members' Council: Aj. Allnutt, P. Dwyer-Hickey, R. fuller, l. Greatwood. B. jackson, J. Kessler, j. Monnickendam, L. Music, l.B. Nelson, P.G. Read, R. Shepherd, C.H. VVinter Branch Chairmen: Midlands - C.M. Green, North West - I. Knight, Scottish - B. jackson Examiners: A.j. Allnutt, M.Sc., Ph.D., leA, S.M. Anderson, B.Se. (Hons), I-CA, L. Bartlett, 13.Se, .'vI.phil., I-G/\' DCi\, E.M. Bruton, FGA, DC/\, c.~. Cavey, FGA, S. Coelho, B.Se, I-G,\' DGt\, Prof. A.T. Collins, B.Sc, Ph.D, A.G. Good, FGA, f1GA, Cj.E. Halt B.Sc. (Hons), FGr\, G.M. Howe, FG,'\, oo-, G.H. jones, B.Se, PhD., FCA, M. Newton, B.Se, D.PhiL, H.L. Plumb, B.Sc., ICA, DCA, R.D. Ross, B.5e, I-GA, DGA, P..A.. Sadler, 13.5c., IGA, DCA, E. Stern, I'GA, DC/\, Prof. I.
    [Show full text]
  • Thirty-Fourth List of New Mineral Names
    MINERALOGICAL MAGAZINE, DECEMBER 1986, VOL. 50, PP. 741-61 Thirty-fourth list of new mineral names E. E. FEJER Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD THE present list contains 181 entries. Of these 148 are Alacranite. V. I. Popova, V. A. Popov, A. Clark, valid species, most of which have been approved by the V. O. Polyakov, and S. E. Borisovskii, 1986. Zap. IMA Commission on New Minerals and Mineral Names, 115, 360. First found at Alacran, Pampa Larga, 17 are misspellings or erroneous transliterations, 9 are Chile by A. H. Clark in 1970 (rejected by IMA names published without IMA approval, 4 are variety because of insufficient data), then in 1980 at the names, 2 are spelling corrections, and one is a name applied to gem material. As in previous lists, contractions caldera of Uzon volcano, Kamchatka, USSR, as are used for the names of frequently cited journals and yellowish orange equant crystals up to 0.5 ram, other publications are abbreviated in italic. sometimes flattened on {100} with {100}, {111}, {ill}, and {110} faces, adamantine to greasy Abhurite. J. J. Matzko, H. T. Evans Jr., M. E. Mrose, lustre, poor {100} cleavage, brittle, H 1 Mono- and P. Aruscavage, 1985. C.M. 23, 233. At a clinic, P2/c, a 9.89(2), b 9.73(2), c 9.13(1) A, depth c.35 m, in an arm of the Red Sea, known as fl 101.84(5) ~ Z = 2; Dobs. 3.43(5), D~alr 3.43; Sharm Abhur, c.30 km north of Jiddah, Saudi reflectances and microhardness given.
    [Show full text]
  • SSEF FACETTE No. 12 SWISS GEMMOLOGICAL INSTITUTE SCHWEIZERISCHES GEMMOLOGISCHES INSTITUT INSTITUT SUISSE DE GEMMOLOGIE
    SSEF FACETTE No. 12 SWISS GEMMOLOGICAL INSTITUTE SCHWEIZERISCHES GEMMOLOGISCHES INSTITUT INSTITUT SUISSE DE GEMMOLOGIE International Issue No. 12, January 2005 Reproduction allowed with reference to the Swiss Gemmological Institute SSEF In this Issue: - Diamonds are forever - New Diamond Courses 2005 - Coral en Vogue - LIBS in Gemmology - Lead glass in Ruby - New: Launching of SSEF Alumni - News from CIBJO and LMHC - GemmoBasel 2005 SSEF Facette No. 12, © 2005 Editorial Dear Reader The year 2004 was again packed with many inter- pearl research in China, instrumental development esting challenges for the SSEF laboratory but also in Florida, diamond conference in England, SSEF for the trade. We are lucky that business for the is always on the edge. And you may profit from SSEF was much better than predicted under tight this: SSEF is proud to have found a new analyti- general conditions. The high performance and the cal solution for the detection of beryllium diffusion degree of integrity of the SSEF is appreciated by a treated sapphires, which caused so much concern number of well-known international companies. We and “headache” to the international gem trade. The notice with pleasure that our origin determinations SSEF is the first laboratory offering an inexpensive and treatment identifications form an important part and reliable Be detection service. of our activity and strongly influence the price of a gem. Reliable SSEF We are glad to offer you the SSEF Facette in a new Test Reports for pearls and colourful look. We are continuing to produce guarantee the trade with this newsletter in three languages: German, French sometimes extremely and English.
    [Show full text]
  • New Minerals Approved Bythe Ima Commission on New
    NEW MINERALS APPROVED BY THE IMA COMMISSION ON NEW MINERALS AND MINERAL NAMES ALLABOGDANITE, (Fe,Ni)l Allabogdanite, a mineral dimorphous with barringerite, was discovered in the Onello iron meteorite (Ni-rich ataxite) found in 1997 in the alluvium of the Bol'shoy Dolguchan River, a tributary of the Onello River, Aldan River basin, South Yakutia (Republic of Sakha- Yakutia), Russia. The mineral occurs as light straw-yellow, with strong metallic luster, lamellar crystals up to 0.0 I x 0.1 x 0.4 rnrn, typically twinned, in plessite. Associated minerals are nickel phosphide, schreibersite, awaruite and graphite (Britvin e.a., 2002b). Name: in honour of Alia Nikolaevna BOG DAN OVA (1947-2004), Russian crys- tallographer, for her contribution to the study of new minerals; Geological Institute of Kola Science Center of Russian Academy of Sciences, Apatity. fMA No.: 2000-038. TS: PU 1/18632. ALLOCHALCOSELITE, Cu+Cu~+PbOZ(Se03)P5 Allochalcoselite was found in the fumarole products of the Second cinder cone, Northern Breakthrought of the Tolbachik Main Fracture Eruption (1975-1976), Tolbachik Volcano, Kamchatka, Russia. It occurs as transparent dark brown pris- matic crystals up to 0.1 mm long. Associated minerals are cotunnite, sofiite, ilin- skite, georgbokiite and burn site (Vergasova e.a., 2005). Name: for the chemical composition: presence of selenium and different oxidation states of copper, from the Greek aA.Ao~(different) and xaAxo~ (copper). fMA No.: 2004-025. TS: no reliable information. ALSAKHAROVITE-Zn, NaSrKZn(Ti,Nb)JSi401ZJz(0,OH)4·7HzO photo 1 Labuntsovite group Alsakharovite-Zn was discovered in the Pegmatite #45, Lepkhe-Nel'm MI.
    [Show full text]
  • Pegasus 3Dvdboxes.Pdf
    BRITAIN AT WAR - OUR FINEST HOURS DISC ONE - D-DAY - ASSAULT ON FORTRESS EUROPE Early in the morning of 6th June 1944, a vast and bizarre armada ploughed steadily against stiff head-winds through the rough waters of the English Channel, heading for the Normandy coast. Amongst the 5,000 vessels were many of the best British and American warships of stupendous collective firepower, as well as ancient battleships and tankers on their last voyage, destined to be sunk to provide breakwaters. Thousands of the craft had been built to make one short journey only; to ferry the invading allied forces, together with their immense diversity of equipment on the last difficult, dangerous stretch from the transports to the shore of enemy-occupied France. It was D-Day. DISC TWO - BATTLE OF BRITAIN - THE FIGHT FOR THE SKY With the surrender of France on 22nd of June 1940, Britain and her Commonwealth stood alone against the might of the German armed forces. In that dark summer of 1940, the threat of invasion hung heavily over Britain and children were once more evacuated to the countryside. The army was still recovering from its defeats in France and could offer no real defence against invasion. Britain had a strategy to meet the German threat, which was due to one man, Air Chief Marshall Sir Hugh Dowding. Against enormous internal pressure, Dowding had resisted committing the majority of his Spitfire and Hurricane squadrons to the battle on the Continent, knowing that the major battle was yet to come - the battle for Britain itself.
    [Show full text]
  • Gemstones by Donald W
    GEMSTONES By Donald W. olson Domestic survey data and tables were prepared by Nicholas A. Muniz, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator. In this report, the terms “gem” and “gemstone” mean any gemstones and on the cutting and polishing of large diamond mineral or organic material (such as amber, pearl, petrified wood, stones. Industry employment is estimated to range from 1,000 to and shell) used for personal adornment, display, or object of art ,500 workers (U.S. International Trade Commission, 1997, p. 1). because it possesses beauty, durability, and rarity. Of more than Most natural gemstone producers in the United states 4,000 mineral species, only about 100 possess all these attributes and are small businesses that are widely dispersed and operate are considered to be gemstones. Silicates other than quartz are the independently. the small producers probably have an average largest group of gemstones; oxides and quartz are the second largest of less than three employees, including those who only work (table 1). Gemstones are subdivided into diamond and colored part time. the number of gemstone mines operating from gemstones, which in this report designates all natural nondiamond year to year fluctuates because the uncertainty associated with gems. In addition, laboratory-created gemstones, cultured pearls, the discovery and marketing of gem-quality minerals makes and gemstone simulants are discussed but are treated separately it difficult to obtain financing for developing and sustaining from natural gemstones (table 2). Trade data in this report are economically viable deposits (U.S.
    [Show full text]
  • GEOGRAPHY Grade 11 (For Grade 11, Commencing from 2008)
    GEOGRAPHY Grade 11 (for Grade 11, commencing from 2008) Teachers' Instructional Manual Department of Social Sciences Faculty of Languages, Humanities and Social Sciences National Institute of Education Maharagama. 2008 i Geography Grade 11 Teachers’ Instructional Manual © National Institute of Education First Print in 2007 Faculty of Languages, Humanities and Social Sciences Department of Social Science National Institute of Education Printing: The Press, National Institute of Education, Maharagama. ii Forward Being the first revision of the Curriculum for the new millenium, this could be regarded as an approach to overcome a few problems in the school system existing at present. This curriculum is planned with the aim of avoiding individual and social weaknesses as well as in the way of thinking that the present day youth are confronted. When considering the system of education in Asia, Sri Lanka was in the forefront in the field of education a few years back. But at present the countries in Asia have advanced over Sri Lanka. Taking decisions based on the existing system and presenting the same repeatedly without a new vision is one reason for this backwardness. The officers of the National Institute of Education have taken courage to revise the curriculum with a new vision to overcome this situation. The objectives of the New Curriculum have been designed to enable the pupil population to develop their competencies by way of new knowledge through exploration based on their existing knowledge. A perfectly new vision in the teachers’ role is essential for this task. In place of the existing teacher-centred method, a pupil-centred method based on activities and competencies is expected from this new educa- tional process in which teachers should be prepared to face challenges.
    [Show full text]
  • Chatting Sri Lanka: Powerful Communications in Colonial Times
    Chatting Sri Lanka: Powerful Communications in Colonial Times Justin Siefert PhD 2016 Chatting Sri Lanka: Powerful Communications in Colonial Times Justin Siefert A thesis submitted in partial fulfilment of the requirements of the Manchester Metropolitan University for the degree of Doctor of Philosophy Department of History, Politics and Philosophy Manchester Metropolitan University 2016 Abstract: The thesis argues that the telephone had a significant impact upon colonial society in Sri Lanka. In the emergence and expansion of a telephone network two phases can be distinguished: in the first phase (1880-1914), the government began to construct telephone networks in Colombo and other major towns, and built trunk lines between them. Simultaneously, planters began to establish and run local telephone networks in the planting districts. In this initial period, Sri Lanka’s emerging telephone network owed its construction, financing and running mostly to the planting community. The telephone was a ‘tool of the Empire’ only in the sense that the government eventually joined forces with the influential planting and commercial communities, including many members of the indigenous elite, who had demanded telephone services for their own purposes. However, during the second phase (1919-1939), as more and more telephone networks emerged in the planting districts, government became more proactive in the construction of an island-wide telephone network, which then reflected colonial hierarchies and power structures. Finally in 1935, Sri Lanka was connected to the Empire’s international telephone network. One of the core challenges for this pioneer work is of methodological nature: a telephone call leaves no written or oral source behind.
    [Show full text]