GEMSTONES with ALEXANDRITE EFFECT by E
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Heat Treating Corundum: the Bangkok Operation
HEAT TREATING CORUNDUM: THE BANGKOK OPERATION By Jack S. D. Abraham Following LIP on Nassau's 1981 article on Banglzolz gem dealer buys a lo+-ct ruby for a six- the technical aspects of heat treating ruby A figure sum and heats it hoping to improve its color and sapphire, the author reports his and value. After one heating, the stone dulls and cannot personal observations of the actual heat be sold for half of its original price. But a few tries later treatment process in Bangkok. He the stone is so improved that a major European dealer discusses the potential effects that this buys it for almost five times the original amount- process can have on a stone-both positive and negative-and emphasizes lznowing that it has been heat treated. the importance of the natural make-up of Another Thai dealer pays a large sum for a 600-ct piece the stone itself to the success of heot of sapphire rough. He then cuts it into four sections and treatment. heats each. For the largest piece, which is over 100 ctl he receives 20% more than he paid for the entire original stone-again from a buyer who knows the stone is heated. A third dealer, however, heats a sapphire for which he has paid a six-figure sum but instead of enhancing the color, the treatment causes the stone to brealz into several pieces. It is now worth a fraction of its original price. Such incidents suggest that the heating of ruby and sapphire has become a fully acceptedl if very rislzyl fact of life in the Far East. -
Elimination of Ferric Ion Effect on Separation Between Kyanite and Quartz Using Citric Acid As Regulator
minerals Article Elimination of Ferric Ion Effect on Separation between Kyanite and Quartz Using Citric Acid as Regulator Yanping Niu 1, Ya Li 1, Haoran Sun 2,*, Chuanyao Sun 3, Wanzhong Yin 2 and Hongfeng Xu 4 1 Heilongjiang Province Geology Ore Test and Application Institute, Harbin 150000, China; [email protected] (Y.N.); [email protected] (Y.L.) 2 College of Resources and Civil Engineering, Northeastern University, Shenyang 110816, China; [email protected] 3 State Key Laboratory of Mineral Processing, BGRIMM Technology Group, Beijing 100160, China; [email protected] 4 Heilongjiang Mining Group Co., Ltd., Harbin 150000, China; [email protected] * Correspondence: [email protected]; Tel.: +86-188-4250-4743 Abstract: Ferric ions produced during grinding influence the flotation separation between kyanite and quartz adversely. In this study, citric acid was used as a regulator to eliminate the effect of ferric ions on the separation of kyanite from quartz with sodium oleate (NaOL) as a collector. The microflotation test results indicated that the quartz was selectively activated by FeCl3 and maintained significant quartz recovery. However, the citric acid could selectively eliminate the effect of ferric ions on the quartz and minimally influenced the kyanite. Contact angle tests demonstrated that FeCl significantly increased the interaction between NaOL and quartz, resulting in the high 3 hydrophobicity of quartz, and the addition of citric acid made the quartz surface hydrophilic again but slightly influenced the kyanite. Fourier-transform infrared spectroscopy showed that FeCl Citation: Niu, Y.; Li, Y.; Sun, H.; Sun, 3 C.; Yin, W.; Xu, H. Elimination of facilitated NaOL adsorption onto the quartz surface, and the addition of citric acid eliminated the Ferric Ion Effect on Separation activation of FeCl3 on the quartz, resulting in the nonadsorption of NaOL onto the quartz surface. -
SGG Corundum Treatment.Pptx
The beauty of colour © Swiss Gemmological Institute SSEF SGG Zentralkurs, Thun, 15. April 2013 Treatment of corundum characteristics, detection and declaration Michael S. Krzemnicki Swiss Gemmological Institute SSEF Switzerland Photos and figures © H.A. Hänni & M.S. Krzemnicki 1! Consumer+expectation+ Quality& Every&gemstone&deposit&produces&stones&of&high&and&low&quality.& Usually&the&quality&distribution&has&the&shape&of&a&pyramid.&& Top&stones&are&rare,&stones&of&lower&quality&are&very&abundant.& The&exploitation&of&gems&is&expensive,®ardless&of&their&quality.& It&is&economically&and&important&to&be&able&to&enhance&stones&of&& the&lower&part&of&the&quality&pyramid&(also&for&the&miners!)& Once&a&treatment&is&developed&and&successfull,&it&often&is&also&applied&& on&stones&of&better&quality&to&make&them&even&better&looking.& Gem$deposit+production+ Quantity& © SSEF Swiss Gemmological Institute Treatment options for corundum... To&modify&transparency:&& &F&Gilling&of&Gissures&with&colourless&substance&&(oil,&artiGicial&resin,&glass)& &F&heating&to&dissolve&inclusions& & To&modify&colour& &F&Gilling&of&Gissures&with&coloured&substance&(oil,&artiGicial&resin,&glass)& &F&heating&in&oxidising&or&reducing&conditions&(±&with&additives)& &F&diffusion&of&„colouring“&elements&into&the&corundum&lattice& &F&irradiation& & To&enhance&stability& &F&Gilling&of&Gissures/cavities&with&solidifyig&substances&& & To&create&optical&effects&& &F&heating&with&additives& & © SSEF Swiss Gemmological Institute! 2! Treatment options for corundum... Fissure&Gilling&and&dyeing& & Foiling,&Painting& Heating&with&blowFpipe& ©&F.&Notari& Heating&with&electrical&furnace& ©&H.A.&Hänni& Irradiation& Heating&combined&with&surface&diffusion& Heating&with&borax&to&induce&Gissure&„healing“& Beryllium&diffusion& LeadFglass&Gissure&Gilling& & CobaltFglass&Gissure&Gilling& & next&treatment&??& & future& 0& 1000& 1900& 2000& Time+scale+ & © SSEF Swiss Gemmological Institute! Treatment options for corundum.. -
Some Uncommon Sapphire “Imitations”: Blue Co-Zirconia, Kyanite & Blue Dumortierite Dr Michael S
Some Uncommon Sapphire “Imitations”: Blue Co-zirconia, Kyanite & Blue Dumortierite Dr Michael S. Krzemnicki Swiss Gemmological Institute SSEF [email protected] 筆者滙報數個瑞士珠寶研究院(SSEF)近期收到 in the ring showed a negative RI reading 要求鑑證的藍色寶石,經檢測後確定其中包括 (above 1.79), an isotropic optical character 一些非常罕見的藍寶石模擬石:含錮氧化鋯、 (polariscope) and thus no pleochroism at all. 藍晶石及藍線石等。 Under the microscope, we saw no inclusions, however a slightly greenish reaction under Sapphires are among the most abundant gems the LWSW and there was a weaker similar we receive at the Swiss Gemmological Institute reaction under SWUV lamps. Based on these (SSEF) for testing. From time to time, however, properties and a chemical analysis by X-ray we are quite surprised by the imitations which fluorescence (EDXRF), the blue stone was we find among the goods sent in and this can readily identified as cubic zirconia (ZrO2). then be disappointing news for the clients. In Having seen this artificial product in a wide the following short note, the author presents a range of colours, the author had not previously few uncommon imitations identified recently at seen one of such a saturated and attractive the SSEF. Identification of these imitations is blue. Based on literature (Nassau 1981) the straightforward and should be no problem for analysed traces of cobalt in that stone have any experienced gemmologist. been identified as the colouring element in this specimen. The absorption spectrum of the stone The first case is that of an attractive blue (Fig. 2) – although superposed by several rare faceted stone of approximately 1.4 ct, set in a ring with diamonds (Fig. -
Compilation of Reported Sapphire Occurrences in Montana
Report of Investigation 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg 2015 Cover photo by Richard Berg. Sapphires (very pale green and colorless) concentrated by panning. The small red grains are garnets, commonly found with sapphires in western Montana, and the black sand is mainly magnetite. Compilation of Reported Sapphire Occurrences, RI 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg Montana Bureau of Mines and Geology MBMG Report of Investigation 23 2015 i Compilation of Reported Sapphire Occurrences, RI 23 TABLE OF CONTENTS Introduction ............................................................................................................................1 Descriptions of Occurrences ..................................................................................................7 Selected Bibliography of Articles on Montana Sapphires ................................................... 75 General Montana ............................................................................................................75 Yogo ................................................................................................................................ 75 Southwestern Montana Alluvial Deposits........................................................................ 76 Specifi cally Rock Creek sapphire district ........................................................................ 76 Specifi cally Dry Cottonwood Creek deposit and the Butte area .................................... -
Metamorphic and Metasomatic Kyanite-Bearing Mineral
Metamorphic and Metasomatic Kyanite-Bearing Mineral Assemblages of Thassos Island (Rhodope, Greece) Alexandre Tarantola, Panagiotis Voudouris, Aurélien Eglinger, Christophe Scheffer, Kimberly Trebus, Marie Bitte, Benjamin Rondeau, Constantinos Mavrogonatos, Ian Graham, Marius Etienne, et al. To cite this version: Alexandre Tarantola, Panagiotis Voudouris, Aurélien Eglinger, Christophe Scheffer, Kimberly Tre- bus, et al.. Metamorphic and Metasomatic Kyanite-Bearing Mineral Assemblages of Thassos Island (Rhodope, Greece). Minerals, MDPI, 2019, 10.3390/min9040252. hal-02932247 HAL Id: hal-02932247 https://hal.archives-ouvertes.fr/hal-02932247 Submitted on 7 Sep 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. minerals Article Metamorphic and Metasomatic Kyanite-Bearing Mineral Assemblages of Thassos Island (Rhodope, Greece) Alexandre Tarantola 1,* , Panagiotis Voudouris 2 , Aurélien Eglinger 1, Christophe Scheffer 1,3, Kimberly Trebus 1, Marie Bitte 1, Benjamin Rondeau 4 , Constantinos Mavrogonatos 2 , Ian Graham 5, Marius Etienne 1 and Chantal Peiffert -
Gemstones in Metal Clay
Gemstones in Metal Clay Many natural gemstones can be set into metal clay and fired in place. Other gemstones will not survive the heat of a kiln and should be set after firing. These charts show the results of kiln and torch tests that have been performed on both natural and synthetic gemstones, adapted with permission from the original testing by Kevin Whitmore of Rio Grande. This information is for reference and should be used as a guide. There is always some risk of losing a natural gemstone even if others of it’s kind have survived in the past. Gemstones may have internal flaws that can be liquid or gaseous filled, or contain crystals of other materials that can cause the gemstone to fail where it usually does not. This guide aims to help metal clay artists sort out gemstones that are known to survive under fire from those that are not. Gemstones are minerals that are classified into groups based upon the constancy of their major properties. Each mineral family has one or more varieties contained within the group. When we sort the tested gemstones according to their mineral group, it becomes clear that an easy way to gauge the survivability of a gemstone is to look at the results of other varieties within that same group. Aquamarine and emerald, for example, are both varieties of the beryl group of minerals. The result of tests done on aquamarine and emerald indicate that minerals in the beryl group will not survive kiln heating. There are exceptions, as there always are in the natural world, but in general this method can be reliable for many varieties. -
Mineral Collecting Sites in North Carolina by W
.'.' .., Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie RUTILE GUMMITE IN GARNET RUBY CORUNDUM GOLD TORBERNITE GARNET IN MICA ANATASE RUTILE AJTUNITE AND TORBERNITE THULITE AND PYRITE MONAZITE EMERALD CUPRITE SMOKY QUARTZ ZIRCON TORBERNITE ~/ UBRAR'l USE ONLV ,~O NOT REMOVE. fROM LIBRARY N. C. GEOLOGICAL SUHVEY Information Circular 24 Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie Raleigh 1978 Second Printing 1980. Additional copies of this publication may be obtained from: North CarOlina Department of Natural Resources and Community Development Geological Survey Section P. O. Box 27687 ~ Raleigh. N. C. 27611 1823 --~- GEOLOGICAL SURVEY SECTION The Geological Survey Section shall, by law"...make such exami nation, survey, and mapping of the geology, mineralogy, and topo graphy of the state, including their industrial and economic utilization as it may consider necessary." In carrying out its duties under this law, the section promotes the wise conservation and use of mineral resources by industry, commerce, agriculture, and other governmental agencies for the general welfare of the citizens of North Carolina. The Section conducts a number of basic and applied research projects in environmental resource planning, mineral resource explora tion, mineral statistics, and systematic geologic mapping. Services constitute a major portion ofthe Sections's activities and include identi fying rock and mineral samples submitted by the citizens of the state and providing consulting services and specially prepared reports to other agencies that require geological information. The Geological Survey Section publishes results of research in a series of Bulletins, Economic Papers, Information Circulars, Educa tional Series, Geologic Maps, and Special Publications. -
KYANITE Al2sio5 a Common Metamorphic Mineral Found Primarily in Regionally Metamorphosed Intermediate-Grade Rocks Derived from Shales
KYANITE Al2SiO5 A common metamorphic mineral found primarily in regionally metamorphosed intermediate-grade rocks derived from shales. It is less common in some veins and pegmatites. Kyanite is very rare in Michigan. It sometimes occurs as a detrital accessory mineral in glacial sands. Northern and Southern Peninsulas. Genesee County: SW ¼ NW ¼ section 6, T8N, R7E: As a detrital accessory in glacial lake sand in a water well (Stewart, 1937). Iron County: The Lake Ellen kimberlite, SW ¼ section 27, T44N, R31W, contains a variety of megacrysts, xenocrysts, and xenoliths (Cannon and Mudrey, 1981; McGee and Hearn, 1983; McGee, 1984; Hearn and McGee, 1985). About 85% of the upper mantle xenoliths collected are eclogites with granulitic textures. Most of these contain only garnet, clinopyroxene, and rutile, but some also have kyanite + sanidine + corundum + sulfides. The very pale blue-to-white kyanite is in 1 mm blades. In one specimen these have a subparallel orientation. An analysis is given in McGee and Hearn (1983). The presence of kyanite in the eclogite xenoliths indicates pressures were at least 18 to 20 kb (kimberlite). Marquette County: Champion mine on 36th level drift. Sky-blue kyanite has been reported in association with coarse, massive andalusite, and orthoclase, muscovite, quartz, biotite, and chlorite (Babcock, 1966a, b). At least one such specimen, however, has been shown by X-ray diffraction to be blue corundum (q.v.). Menominee County: Site 73 kimberlite, north of Hermansville: Small pale blue kyanite crystals have been recovered from heavy mineral concentrates produced from this kimberlite (S. M. Carlson, written communication, 1997). FROM: Robinson, G.W., 2004 Mineralogy of Michigan by E.W. -
Reflective Index Reference Chart
REFLECTIVE INDEX REFERENCE CHART FOR PRESIDIUM DUO TESTER (PDT) Reflective Index Refractive Reflective Index Refractive Reflective Index Refractive Gemstone on PDT/PRM Index Gemstone on PDT/PRM Index Gemstone on PDT/PRM Index Fluorite 16 - 18 1.434 - 1.434 Emerald 26 - 29 1.580 - 1.580 Corundum 34 - 43 1.762 - 1.770 Opal 17 - 19 1.450 - 1.450 Verdite 26 - 29 1.580 - 1.580 Idocrase 35 - 39 1.713 - 1.718 ? Glass 17 - 54 1.440 - 1.900 Brazilianite 27 - 32 1.602 - 1.621 Spinel 36 - 39 1.718 - 1.718 How does your Presidium tester Plastic 18 - 38 1.460 - 1.700 Rhodochrosite 27 - 48 1.597 - 1.817 TL Grossularite Garnet 36 - 40 1.720 - 1.720 Sodalite 19 - 21 1.483 - 1.483 Actinolite 28 - 33 1.614 - 1.642 Kyanite 36 - 41 1.716 - 1.731 work to get R.I. values? Lapis-lazuli 20 - 23 1.500 - 1.500 Nephrite 28 - 33 1.606 - 1.632 Rhodonite 37 - 41 1.730 - 1.740 Reflective indices developed by Presidium can Moldavite 20 - 23 1.500 - 1.500 Turquoise 28 - 34 1.610 - 1.650 TP Grossularite Garnet (Hessonite) 37 - 41 1.740 - 1.740 be matched in this table to the corresponding Obsidian 20 - 23 1.500 - 1.500 Topaz (Blue, White) 29 - 32 1.619 - 1.627 Chrysoberyl (Alexandrite) 38 - 42 1.746 - 1.755 common Refractive Index values to get the Calcite 20 - 35 1.486 - 1.658 Danburite 29 - 33 1.630 - 1.636 Pyrope Garnet 38 - 42 1.746 - 1.746 R.I value of the gemstone. -
Spring 1995 Gems & Gemology
TABLE CONTENTS FEATURE ARTICLES 2 Rubies from Mong Hsu Adolf Pelsetti, I(ar7 Schmetzer, Heinz-Jiirgen Bernhardt, and Fred Mouawad " 28 The Yogo Sapphire Deposit Keith A. ~~chaluk NOTES AND NEW TECHNIQUES 42 Meerschaum from Eskisehir Province, Turkey I<adir Sariiz and Islcender Isilc REGULAR FEATURES 52 Gem Trade Lab Notes Gem News Most Valuable Article Award Gems ed Gemology Challenge Book Reviews Gemological Abstracts Guidelines for Authors ABOUT THE COVER: One of the most important ruby localities of the 1990s cov- ers a broad orea near the town of Mong Hsu, in northeastern Myann~ar(B~lrrna). The distinctive gemological features of these rubies are detailed in this issue's lead article. The suite of fine jewelry illustraled here contains 36 Mong Hsu rubies with a total weigh1 of 65.90 ct; the two rubies in the ring total 5.23 ct. jewelry courtesy of Mouawad jewellers. Photo by Opass Sultsumboon-Opass Suksuniboon Studio, Bangltolz, Thailand. Typesetting for Gerrls eS Gemology is by Graphix Express, Santa Monica, CA. Color separations are by Effective Graphics, Compton, CA. Printing is by Cadmus lournal Services, Easton, MD. 0 1995 Gemological Institute of America All rights reserved ISSN 0016-626X - Editor-in-Chief Editor Editors, Gem Trade Lab Notes Richard T. Lidtlicoat Alicc S. I<cller Robcrt C. I<ammerling 1660 Stewart St. C. W. Fryer Associate Editors Smta Mon~ca,CA 90404 William E. Boyajian Editors, Gem News (800)421-7250 ~251 Robcrt C. Kamn~erling Rohcrt C. I<ammerling e-mail: altellcrBclass.org D. Vincent Manson John I. Koivula John Sinltanltas Sr~bscriptions Enirnanuel Fritsch Jln Ll~n Editors, Book llevielvs Technical Editor (800) 421-7250 x201 Susan B. -
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American Mineralogist, Volume 63, pages 664_676, l97g Multisyste_msanalysis of beryiliumminerar stabilities: the systemBeO-A[rOa_SiO2_H2O DoNer.n M. Bunr Department of Geology, Arizona State (Jniuersitv Tempe,Arizona8528I Abstract seven commonly associatedminerals in the systemBeo-Alror-Sior-Hro includechry- soberyl,phenakite, euclase,bertrandite, beryl, kaolinite,and qiuit . The phaserule implies that not more than six of theseminerals can coexistat an invariantpoint, and, with the addition of an aqueousphase, the associationconstitutes an (n * 4; ptrase(negative two d-egreesof freedom)multisystem. The apparentincompatibility of taotinite with phenakite allowsthe splitting of this unwieldymultisystem into two smaller(n + 3) phasemultisystems, which may belabeled (Kao) and (phe).Moiar volumedata, compuier program RrlcrroN, and naturalassemblages can then be usedto derivethe presumablystabie cJnfiguration of these multisystemson p"-minus an isothermal pHro diagram. n, p-r diagramprojected through theaqueous phase shouldhave the sametopology, and cansimilarlf be drawn. on the resultingdiagrams, three . invariant-butpoinis rabeled tchrl, tBr;;, and [etz] arestable in the.multisystem (Kao), and threedistinct identically-fuU"i.Opoint, u.. stablein rhe multisystem(Phe). An implicationof this topologyvia ihe "r.tu.tubl"-rtable correspon- dence,"is that the assemblagephenakite + euclase* beryl(* aqueousphase) has a finite i'I;ix, ii,l'J.?lT"t' ::ff,,,j :r;: :":.T' ? ts why" euclase is muchrarer than bertrandite. and its stabilityfield, especially