 | | Journal (issue) | | inclusions or these cannot be seen because the host gem is too opaque. The brownish opal termed hyalite,...KennethScarratt, Kenneth Scarratt, F.G.A. F.G.A. The Gem Gem Testing Testing Laboratory Laboratory of of Great...Laboratory's name that has changed, firstly from 'The Gem Testing Laboratory of the London Chamber of of Commerce...Commerce and Industry' and then to 'The British Gem Testing Laboratory of the London Chamber ofCommerce...The The Laboratory Laboratory is now known as 'The Gem Testing Laboratory of of Great Britain'.. Britain' |  | | Journal (article/letter/editorial) | | A DAY IN A CEYLON GEM FIELD Delaware' Josoru L. GrlrsoN, Wilmi'ngton, In March, 1932, having two free...arrangementsto quickly visit Ratnapura, 55 miles southeast of Colombo, the center of the gem-washing injourney in...to show me the promised who found was guide a Ratnapura, and in operation durstill were that places) (washing...idamas daYs. these depression ing-ttrat the -eylo.t gem fields have been known for a very long time is indicated...plagiarizes the tale in a more interesting manner'"1 Ratnapura (a Singhalese word meaning "City of Gems") is |  | | Book | | assemblage such as the zeolites from India, or high gem quality such as the rubies from Burma, or some significantly...notable example in this category is the Nuristan District of Afghanistan, which over the past 10 years has...has produced some of the most extraordinary gem minerals ever found. The majority of this volume is based...Saijo, Iyo Province, Ehime Prefecture, Island of Shikoku Ashio Mine, Shimotsuke Province, Tochigi Prefecture...Arakawa Mines, Ugo Province, Akita Prefecture, Honshu The Obira Mine, Bungo Province, Oita Prefecture, |  | | Report (issue) | | —The Mineral Resources of the North-West Frontier Province. By A. L. Coulson. (Prioe As. 14 or la. 3d.) No...paper, “ Notes on Indian Precious Stones ”. Notes on Gem Stones have also been included in the Quinquennial...publications, also deals in addition with the use of the gem materials, their grades, overseas and Indian occurrences...in the above mentioned publications. Besides only gem materials of inorganic nature or minerals have been...Stones. CONTENTS. Paces. I F I. Introduction . Gem materials Imitation gems Synthetic gems II. Properties |  | | Book | | Properties of crystals Gem crystals 18 19 19 20 20 21 22 32 33 3 3.1 3.2 3.3 Gem testing Hardness Gemstones...56 4 4.1 4.2 4.3 4.4 4.5 Recent developments in gem testing 59 59 60 61 64 65 Thermal conductivity...understandably and rightly, with the science of gem testing and have covered that area very well. Details...entirely new gem mineral species have been found in the last few years; tanzanite, appearing on the gem market...with no gem potential whatever. It is not likely that many entirely new mineral species with gem application | | | Book | | structure Properties of crystals Gem crystals 19 19 20 20 21 22 32 33 3 Gem testing Hardness Gemstones and...Specific gravity 36 37 56 4 Recent developments in gem testing Thermal conductivity Measurement of refractive...understandably and rightly, with the science of gem testing and have covered that area very well. Details...entirely new gem mineral species have been found in the last few years; tanzanite, appearing on the gem market...with no gem potential whatever. It is not likely that many entirely new mineral species with gem application |  | | Book (edition) | | EDITION AREM, PH.D., FG.A. gem gemologists, 1977, jewelers, and gem collectors, dealers have relied...INTRODUCTION What / Gem? a / Scope of This Book / Is The Nature Gems of GEM SECTION 1 2 GEMSTONES...Rock Classification Gem Scarcity Intrusive Crystal 6 Growth Synthetic Gem 9 / Gemstones SOURCES...dealers are aware of the growing value of exotic gem species; the list of known taaffeites has thus grown...greater monetary reward than are the tists who gem scien- build detection equipment. Inevitably, a |  | | Journal (article/letter/editorial) | | weighing tens of kilograms have been seen at major gem and mineral shows. Downloaded by [University of...during 2003 are the Mineral Section of the Houston Gem and Mineral Society and the Cincinnati Mineral Society...length have been available from the Alto Chapare district, Cochabamba, Bolivia (Petrov 2003). Here it is...chlorite-included crystals to about 1 cm associated with adularia, apatite, pericline-twinned albite, and quartz...length have been found in the Bor open pit of this district (Grant and Wilson 2001). Other Russian localities |  | | Journal (issue) | | No. 8 / 2019 COLUMNS What’s New 679 ABCD Pro-1 Gem Testing Set | D-Imaging Device | Raman Spectroscopy...| Jewelry Journey Podcasts | Gemewizard Gem Color Academy Gem Notes Amethyst from Zimbabwe | Apatite...Fuchsite Phantom Inclusions | Tourmaline from Sri Lanka with Transient Tenebrescence? | Diving for Natural...710–725 of this issue) and therefore does not have a Sri Lankan origin as commonly described for Roman sapphires...Trapiche Ruby from Khoan Thong, Luc Yen Mining District, Northern Vietnam 726 By Isabella Pignatelli |  | | Book (edition) | | to prepare a new edition of the Guide. Many new gem species have been added to the collections in recent...wherever possible. In a developing world the names of gem-producing countries may change rapidly, but many...in brackets) arc shown in the following list: Sri Lanka (Ceylon), Malagasy Republic (Madagascar), Kampuchea...minerals which are used for orn amental purposes the gem minerals are arranged in a series of exhibits in...topaz, or zircon, which is in vogue; the favoured gem consequently rises in value until some new whim relegates |  | | Book | | culture, derives its name from the saltmining district of Hallstatt in Upper Austria, where many prehistoric... Pl. 40 hornblende, Pl. 44 orthoclase, Pl. 45 adularia, Fig. 23 augite and hornblende, Fig. 24 feldspar;...The sedimentary rocks 1 RESIDUAL ROCKS grit, gravels (in part), weathered clay, laterite, bauxite 2...than 2 mm.): grits and breccias (angular grains), gravels, conglomerates (rounded grains), moraines and tillites...have been concentrated by secondary enrichment. Gravels are partly residual formations and partly elastic |  | | Book | | E YE WI TNES S HA N D B O O KS GEM STONES The visual guide to more than 130 gemstone varieties...org/details/gemstoneseyewitnOOcall EYEWITNESS HANDBOOKS GEM STONES E YE WI TNESS HANDBOOKS GEMSTONES Cally...varieties are found and fashions change. Over 130 gem species, including some exceptionally rare stones...why the species entries in this its book show the gem rough, natural state, perhaps embedded in still...they can be appreciated by anyone, from the amateur gem-spotter to the enthusiast who enjoys their beauty |  | | Book (edition) | | 1 2 The Geological Sources of Gems Crystalline Gem Materials 3 40 Part II 3 4 5 6 7 8 9 10 11 12 13...The Biological Gem Materials The Fashioning of Gemstones Value-Enhanced Gemstones and Gem Materials 292...library for virtually all sources. Derivations of gem and mineral names are not given; they can be found...not now considered valid or current. While many gem collectors collect mineral specimens too, the text...text for the 1994 edition. In this new edition, the gem testing section has been omitted; this information |  | | Book | | if not created, a rapid growth in the hobbies of gem cutting, jewelry making, and mineral collecting....same time people in the jewelry industry and the gem trade have recognized the need for greater technical...description of a great collection, a single gem material, gem cutting, or jewelry mak- ing. In addition...chapter, dealing with the genesis and occurrence of gem minerals, is followed by chapters on the chemical...in their determination. Brief chapters deal with gem inclusions and imperfections, synthesis, imitation |  | | Book | | GEMS Introduction 10 Gem descriptions is ORGANIC GEMS Introduction Z2i2 Gem descriptions 274 SYNTHETIC...SYNTHETIC AND ARTIFICIAL PRODUCTS Introduction 316 Gem descriptions 329 Synoptic Tables 366 Glossary...Probably the first question one tends to ask sbout a gem, as of a mineral, is ‘‘What is it?’’ Some look quite...including the use of a chemical hood and gloves. If a gem under examination is put, for example, into bottle...observations will be sufficient to identify the gem. Where a more precise figure is required, two pairs |  | | Book | | " PP ^ |5& V:.^ jV-. ^: V-. ■• 4* ' N^Sri dr., > A i'-.v ' .1 • , ...,, i ■'>1$ V -...occurs. LEFT This fine example of feldspar variety adularia from Switzerland shows clearly the striations...through a stone. This distance factor is useful to gem cutters, who make light coloured stones thicker to...breakthrough, development work continued until a crystal of gem quality was produced in 1970. However, this process...diamonds \ n II \ K A scene from the which are not of gem quality are still being produced and play an important |  | | Book (edition) | | © Tere crree! THE CLEVER GEM BUYER Sclaolalemcveliareln GAVIN LINSELL “She is more precious than...the main reason invariably is that a particular gem means something special to us: they represent a story...perceptions. Now in its second edition, The Clever Gem Buyer brings the reader not only the ‘gemmological’...in an absorbing and entertaining way, The Clever Gem Buyer’s second edition includes even more gemstone...mountain of gemstone rings’ in Thailand's Chanthaburi Province, an international centre for coloured gemstones | | | Book | | same time people in the jewelry industry and the gem trade have recognized the need for greater technical...description of a great collection, a single gem material, gem cutting, or jewelry making. In addition many...chapter, dealing with the genesis and occurrence of gem minerals, is followed by chapters on the chemical...in their determination. Brief chapters deal with gem inclusions and imperfections, synthesis, imitation...subject and a gem index to facilitate obtaining con1monly sought information; the name in the gem index is |  | | Journal (issue) | | run verticall y or horizontally righ t across the gem surface. Onyx is very popu lar in pe n da n t s an...have been the name of a town in ancient Egypt. A GEM AND A ROCK I I Most alabaster is defined as the...be artificially ""tJ Right: Although the term 'gem' is most commonly associated with the precious mountings...alabaster from Volterra, near Pisa (Italy). This gem material is basically the mineral gypsum. Although...now exhausted, but the gem can still be found in small quantities in Sri Lanka, Burma and Brazil. Alexandrite's |  | | Report (issue) | | this crown was not a ruby, but a tourmaline. The gem in this crown is now the oldest known important tourmaline...of Sri Lankan origin, are estimated to weigh more than 100 carats. The spinels are from Sri Lanka and... the rubies are from either Sri Lanka or Burma and the aquamarine is Sri Lankan. The tourmaline could...until its early eighteenth century arrival on the gem mar kets of Amsterdam, that tourmaline gained notice...from the Cingalese turamali (a mixed collection of gem rough), was introduced in Holland in 1703. The name |  | | Book (edition) | | Forn1ation of Gemstones 26 34 The Description of Gem..~tones contained in the Collection . .. ••• 76 Appendix...(The pearl, although probably the most valuable gem at the present time, is excluded, as it can hardly...topaz, 01"' zircon, which is in vogue ; the favoured gem consequently tlses in value 11nt,il some new whim...Craft,'' by Leopold Claremont. • 1906 . a •• '' Gem-Stones,'' by G. F. H. Smith. 1912. '' Die Farben...polished plates of the minerals 6 to 9 and to rt1b the gem successively over them, beginning with number 6, | | | Book (edition) | | (The pealrl, although probably the most valuable gem at the present time, is excluded, as it can hardly...topaz, or zircon, which is in vogue ; the favoured gem consequently rises in value until some n ew whim...Gemcutter's Craft," by Leopold Claremont. 1906. '' Gem-Stones," by G. F. H. Smith. 1912. '' Die Farben der...polished plates of the minerals 6 to 9 and to rub the gem successively over them, beginning with number 6,...any way. The optical properties characteristic of gem- · stones are conveniently classed as follows : Transparency |  | | Book | | them. Until recently mineral-collecting was the province of the mineralogist, the miner or the wealthy...peninsula in Michigan, U.S.A.; the Lake Superior district, and Cobalt, Ontario. Small amounts have been...Queensland and New South Wales; the Mother Lode district of California and parts of Colorado, U.S.A.; Canada;...Urals; the island of Elba; Burma; the Ceylon gem gravels; Alamos in Mexico ('watermelon' colour-zoned...including: Mt. Mica, Oxford Co., Maine; the Pala district of San Diego Co., California; Haddam Neck, Con¬ |  | | Book | | comparatively large transparent crystals such as those of gem quality minerals) uniaxial minerals will have the...table) play an important part in the colouration of gem minerals although they do not colour anything like...the materials of the case in which they are kept. Gem quality minerals - and there are relatively few of...material is in gravel form (with luck the gem gravels of Sri Lanka) sieve it into a sink, screen it, and...kept dry and away from anything containing sulphur. Gem materials which have had their colour improved may |  | | Book | | GEM _ MINERALS^ of Idaho with field trip j& maps by John A.fl£.jkwith Gem Minerals of Idaho, designed...of the gems. Great areas of public land in the Gem to practically unrestricted exploration Only a...other section of the world gem mineral-forming forces than makes Idaho a gem hunter's para- has experienced...Idaho," a fact that dise. L. AND RUTH M. EVANS GEM AND MINERAL COLLECTION COVER PHOTOS FROM THE GLEN...of quartz, it is usually regarded as a distinct gem species. Opal occurs in several varieties of gemological |
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