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Phase Equilibria and Thermodynamic Properties of Minerals in the Beo
American Mineralogist, Volwne 71, pages 277-300, 1986 Phaseequilibria and thermodynamic properties of mineralsin the BeO-AlrO3-SiO2-H2O(BASH) system,with petrologicapplications Mlnx D. B.qnroN Department of Earth and SpaceSciences, University of California, Los Angeles,Los Angeles,California 90024 Ansrru,cr The phase relations and thermodynamic properties of behoite (Be(OH)r), bertrandite (BeoSirOr(OH)J, beryl (BerAlrSiuO,r),bromellite (BeO), chrysoberyl (BeAl,Oo), euclase (BeAlSiOo(OH)),and phenakite (BerSiOo)have been quantitatively evaluatedfrom a com- bination of new phase-equilibrium, solubility, calorimetric, and volumetric measurements and with data from the literature. The resulting thermodynamic model is consistentwith natural low-variance assemblagesand can be used to interpret many beryllium-mineral occurTences. Reversedhigh-pressure solid-media experimentslocated the positions of four reactions: BerAlrSiuO,,: BeAlrOo * BerSiOo+ 5SiO, (dry) 20BeAlSiOo(OH): 3BerAlrsi6or8+ TBeAlrOo+ 2BerSiOn+ l0HrO 4BeAlSiOo(OH)+ 2SiOr: BerAlrSiuO,,+ BeAlrOo+ 2H2O BerAlrSiuO,,+ 2AlrSiOs : 3BeAlrOa + 8SiO, (water saturated). Aqueous silica concentrationswere determined by reversedexperiments at I kbar for the following sevenreactions: 2BeO + H4SiO4: BerSiOo+ 2H2O 4BeO + 2HoSiOo: BeoSirO'(OH),+ 3HrO BeAlrOo* BerSiOo+ 5H4Sio4: Be3AlrSiuOr8+ loHro 3BeAlrOo+ 8H4SiO4: BerAlrSiuOrs+ 2AlrSiO5+ l6HrO 3BerSiOo+ 2AlrSiO5+ 7H4SiO4: 2BerAlrSiuOr8+ l4H2o aBeAlsioloH) + Bersio4 + 7H4sio4:2BerAlrsiuors + 14Hro 2BeAlrOo+ BerSiOo+ 3H4SiOo: 4BeAlSiOr(OH)+ 4HrO. -
Mineralogy and Geochemistry of Nephrite Jade from Yinggelike Deposit, Altyn Tagh (Xinjiang, NW China)
minerals Article Mineralogy and Geochemistry of Nephrite Jade from Yinggelike Deposit, Altyn Tagh (Xinjiang, NW China) Ying Jiang 1, Guanghai Shi 1,* , Liguo Xu 2 and Xinling Li 3 1 State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China; [email protected] 2 Geological Museum of China, Beijing 100034, China; [email protected] 3 Xinjiang Uygur Autonomous Region Product Quality Supervision and Inspection Institute, Xinjiang 830004, China; [email protected] * Correspondence: [email protected]; Tel.: +86-010-8232-1836 Received: 6 April 2020; Accepted: 6 May 2020; Published: 8 May 2020 Abstract: The historic Yinggelike nephrite jade deposit in the Altyn Tagh Mountains (Xinjiang, NW China) is renowned for its gem-quality nephrite with its characteristic light-yellow to greenish-yellow hue. Despite the extraordinary gemological quality and commercial significance of the Yinggelike nephrite, little work has been done on this nephrite deposit, due to its geographic remoteness and inaccessibility. This contribution presents the first systematic mineralogical and geochemical studies on the Yinggelike nephrite deposit. Electron probe microanalysis, X-ray fluorescence (XRF) spectrometry, inductively coupled plasma mass spectrometry (ICP-MS) and isotope ratio mass spectrometry were used to measure the mineralogy, bulk-rock chemistry and stable (O and H) isotopes characteristics of samples from Yinggelike. Field investigation shows that the Yinggelike nephrite orebody occurs in the dolomitic marble near the intruding granitoids. Petrographic studies and EMPA data indicate that the nephrite is mainly composed of fine-grained tremolite, with accessory pargasite, diopside, epidote, allanite, prehnite, andesine, titanite, zircon, and calcite. Geochemical studies show that all nephrite samples have low bulk-rock Fe/(Fe + Mg) values (0.02–0.05), as well as low Cr (0.81–34.68 ppm), Co (1.10–2.91 ppm), and Ni (0.52–20.15 ppm) contents. -
Economic Dimensions of Precious Metals, Stones, and Feathers: the Aztec State Society
ECONOMIC DIMENSIONS OF PRECIOUS METALS, STONES, AND FEATHERS: THE AZTEC STATE SOCIETY FRANCES F. BERDAN In the spring of 1519, Hernán Cortés and his band of Spanish conquistadores feasted their eyes on the wealth of an empire. While resting on the coast of Veracruz, before venturing inland, Cortés was presented with lavish gifts from the famed Aztec emperor Mocte· zuma IV- While only suggestive of the vastness of imperial wealth, these presents included objects of exquisite workmanship fashioned of prized materials: gold, silver, feathers, jadeite, turquoise.2 There was an enormous wheel of gold, and a smaller one of silver, one said to represent the sun, the other the moon. There were two impressive collars (necklaces) of gold and stone mosaic work: they combined red stones, green stones, and gold bells. s There were fans and other elabo 1 Saville (1920: 20-39, 191-206) provides a detailed summary of the many accounts of the gifts presented to Cortés on this occasion. 2 Up to this point in their adventure, sorne of the conquistadores apparently had been sorely disappointed in the mainland's wealth. Bernal Diaz del Castillo repeatedly refers to the gold encountered by the Hernández de Córdova and Gri jalva expeditions (1517 and 1518, respectively) as "Iow grade" or "inferior", and small in quantity (Díaz del Castillo, 1956: 8, 22,23, 25, 28). While Díaz, writing many years after the events he describes, seems especially critical of the quality of the gold avaiJable on the coast, the friar Juan Díaz's account of the Grijalva ex pedition betrays no such dísappointment. -
Christie's Presents Jewels: the Hong Kong Sale
FOR IMMEDIATE RELEASE October 28, 2008 Contact: Kate Swan Malin +852 2978 9966 [email protected] CHRISTIE’S PRESENTS JEWELS: THE HONG KONG SALE Jewels: The Hong Kong Sale Tuesday, December 2 Christie’s Hong Kong Hong Kong – Christie’s announces the fall sale of magnificent jewellery, Jewels: The Hong Kong Sale, which will take place on December 2 at the Hong Kong Convention and Exhibition Centre. This sale features an exquisite selection of over 300 extraordinary jewels across a spectrum of taste and style, from masterpieces of the Belle Époque to contemporary creations, and from the rarest of white and coloured diamonds to important coloured stones. COLOURLESS DIAMONDS Leading the auction is a rare pair of D colour, Flawless diamonds weighing 16.11 and 16.08 carats (illustrated right, estimate: HK$40,000,000-60,000,000 / US$5,000,000-8,000,000). These marvellous stones are also graded ‘Excellent’ for polish, symmetry and cut grade, making them exceedingly rare for their superb quality. Classified as Type IIa, these diamonds are the most the chemically pure type of diamonds known, with no traces of the colorant nitrogen. The absence of this element, seen in 98% of diamonds, gives these stones a purity of colour and degree of transparency that is observed only in the finest white diamonds. The modern round brilliant cut is the diamond’s most basic and popular shape, as it allows the potential for the highest degree of light return. But more importantly, the round diamond sustains the highest value as its production requires riddance of the greatest amount of diamond rough. -
Heat Capacities and Thermodynamic Functions for Beryl, Beralrsiuotr
American Mineralogist, Volume 7I, pages 557-568, 1986 Heat capacitiesand thermodynamicfunctions for beryl, BerAlrSiuOtr, phenakite, BerSiOn,euclase, BeAlSiOo(OH)' bertranditeo BeoSirOt(OH)r,and chrysoberyl' BeAl2Oa B. S. HnluNcw.q,Y U.S. GeologicalSurvey, Reston, Y irgrnia22092 M. D. B.nnroN Departmentof Earthand SpaceSciences, University of California,Los Angeles,Los Angeles,California 90024 R. A. Ronrn, H. T. HLsnr.roN, Jn. U.S. GeologicalSurvey, Reston, Y irginia22092 Ansrru,cr The heat capacities of beryl, phenakite, euclase,and bertrandite have been measured betweenabout 5 and 800 K by combined quasi-adiabaticcryogenic calorimetry and dif- ferential scanningcalorimetry. The heat capacitiesof chrysoberylhave beenmeasured from 340 to 800 K. The resulting data have been combined with solution and phase-equilibrium experimentaldata and simultaneouslyfit using the program pHAS2oto provide an internally consistent set of thermodynamic properties for several important beryllium phases.The experimentalheat capacitiesand tablesof derived thermodynamic propertiesare presented in this report. The derived thermodynamic properties at I bar and 298.15 K for the stoichiometric beryllium phasesberyl, phenakite, euclase,and bertrandite are entropies of 346.7 + 4.7, 63.37+0.27,89.09+0.40, andl72.l+0.77 J/(mol'K),respectively,andGibbsfree energiesof formation(elements) of -8500.36 + 6.39, -2028.39 + 3.78, -2370.17 + 3.04, and -4300.62 + 5.45 kJlmol, respectively,and, -2176.16 + 3.18kJ/mol for chrysoberyl. The coefficientscr to c, of the heat-capacityfunctions are as follows: valid phase ct c2 c, x 105 c4 c, x 10-6 range beryl 1625.842 -0.425206 12.0318 -20 180.94 6.82544 200-1800K phenakite 428.492 -0.099 582 1.9886 -5 670.47 2.0826 200-1800K euclase 532.920 -0.150729 4.1223 -6726.30 2.1976 200-1800K bertrandite 825.336 -0.099 651 -10 570.31 3.662r7200-1400 K chrysoberyl 362.701 -0.083 527 2.2482 -4033.69 -6.7976 200-1800K whereC!: cr * ctT + crT2 * coT-os* crT-2and Zisinkelvins. -
Riebeckite Na2[(Fe2+,Mg)3Fe 2 ]Si8o22(OH)
2+ 3+ Riebeckite Na2[(Fe ; Mg)3Fe2 ]Si8O22(OH)2 c 2001 Mineral Data Publishing, version 1.2 ° Crystal Data: Monoclinic. Point Group: 2=m: As prismatic crystals, to 20 cm. Commonly ¯brous, asbestiform; earthy, massive. Twinning: Simple or multiple twinning 100 . k f g Physical Properties: Cleavage: Perfect on 110 , intersecting at 56 and 124 ; partings f g ± ± on 100 , 010 . Fracture: [Conchoidal to uneven.] Tenacity: Brittle. Hardness = 6 f g f g D(meas.) = 3.28{3.44 D(calc.) = 3.380 Optical Properties: Semitransparent. Color: Black, dark blue; dark blue to yellow-green in thin section. Luster: Vitreous to silky. Optical Class: Biaxial (+) or ({). Pleochroism: X = blue, indigo; Y = yellowish green, yellow- brown; Z = dark blue. Orientation: Y = b; X c = 8 to 7 ; Z c = 6 {7 . Dispersion: ^ ¡ ± ¡ ± ^ ± ± Strong. ® = 1.656{1.697 ¯ = 1.670{1.708 ° = 1.665{1.740 2V(meas.) = 50±{90±. Cell Data: Space Group: C2=m: a = 9.822 b = 18.07 c = 5.334 ¯ = 103:52± Z = 2 X-ray Powder Pattern: Doubrutscha [Dobrudja], Romania. (ICDD 19-1061). 8.40 (100), 3.12 (55), 2.726 (40), 2.801 (18), 4.51 (16), 2.176 (16), 3.27 (14) Chemistry: (1) (2) (1) (2) SiO2 52.90 50.45 CaO 0.12 0.08 TiO2 0.57 0.14 Li2O 0.54 Al2O3 0.12 1.96 Na2O 6.85 6.80 Fe2O3 17.20 17.52 K2O 0.03 1.48 Cr2O3 0.04 F 2.58 + FeO 17.95 17.90 H2O 0.87 MnO 0.00 1.40 O = F 1.09 ¡ 2 MgO 2.96 0.05 Total 98.74 100.68 (1) Dales Gorge Iron Formation, Western Australia; by electron microprobe, corresponds to 2+ 3+ (Na2:00Ca0:02K0:01)§=2:03(Fe2:26Mg0:66Ti0:06)§=2:98Fe1:95(Si7:98Al0:02)§=8:00O22(OH)2: (2) Pikes 2+ Peak area, Colorado, USA; corresponds to (Na2:02K0:29Ca0:01)§=2:32(Fe2:30Li0:33Mn0:18Al0:10 3+ Ti0:02Mg0:01)§=2:94Fe2:02(Si7:75Al0:25)§=8:00O22[F1:25(OH)0:89]§=2:14: Polymorphism & Series: Forms a series with magnesioriebeckite. -
Simultaneous Diamond, White Sapphire & Moissanite
SIMULTANEOUS DIAMOND, WHITE SAPPHIRE & MOISSANITE TESTER NEW ADVANCED EXCLUSIVE TECHNOLOGY RECOMMENDED by CHARLES & COLVARD CREATED MOISSANITE READ BEFORE USING The new moissanite that was introduced in late 2015 has changed. It can no longer be easily visually identified. It is now D-E-F “colorless”, with few inclusions. More importantly, standard diamond/moissanite testers will identify it as diamond since it is now only very slightly electrically conductive. The UltraTester 3+ uses new technology and is calibrated to identify this faint property. Be aware that body oil is also electrically conductive. Due to the tester’s enhanced sensitivity, dirty diamonds may test as moissanite. To avoid false/positive readings on dirty diamonds, ALWAYS CLEAN THE STONE on a cloth prior to testing. Periodically, also clean any accumulated body oil off of the probe tip by gently rubbing it on uncoated paper - SEE MANUAL. NEED HELP? Call GemOro at 800.527.0719 for immediate assistance. The GemOro UltraTester 3+ is the ultimate tester for diamond fraud protection that’s exclusively RECOMMENDED BY CHARLES & COLVARD, the manufacturer of created moissanite! The UltraTester 3+ features NEW ADVANCED EXCLUSIVE TECHNOLOGY capable of identifying the widest range of the electrically conductive moissanite material available, including the new super-low electrically conductive moissanite. OPERATING PROCEDURE & OWNERS MANUAL Congratulations on your purchase of the UltraTester 3+ from GemOro Superior GEMORO ULTRATESTER 3+ 2 Instruments, the most trusted name in gemological instrumentation for the jewelry industry. You’ve made a great choice. Built upon the foundation of the second generation and most popular tester to date, the UltraTester 3+ offers even more. -
Geochemical Journal, Vol. 55 (No. 4), Pp. 209-222, 2021
Geochemical Journal, Vol. 55, pp. 209 to 222, 2021 doi:10.2343/geochemj.2.0630 10Be/9Be ratios of phenakite and beryl measured via direct Cs sputtering: Implications for selecting suitable Be carrier minerals for the measurement of low-level 10Be ATSUNORI NAKAMURA,1* ATSUYUKI OHTA,1 HIROYUKI MATSUZAKI2 and TAKASHI OKAI1 1Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567, Japan 2Micro Analysis Laboratory, Tandem Accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan (Received December 23, 2020; Accepted April 29, 2021) Preparing Be carrier solutions with low 10Be/9Be ratios is essential for the applications of in-situ-produced cosmogenic 10Be in geochronology. This is because commercially available Be carriers are non-negligibly contaminated by 10Be. Recently, in-house Be carriers have been successfully applied to samples that contain small amounts of in-situ-produced 10Be. The first step in preparing in-house Be carriers is selecting suitable Be-bearing minerals that contain less 10Be. Here, we present a simple method for selecting appropriate raw minerals for in-house Be carriers. That is, measuring the 10Be/ 9 10 9 Be ratios of Be-bearing minerals by direct Cs sputtering. Analyses of the Be/ Be ratios of phenakite (Be2SiO4) and beryl (Be3Al2Si6O18) obtained from a mineral collection at the Geological Survey of Japan indicate that phenakite gener- ally contains more 10B, interfering isobar of 10Be, than beryl. In addition to the necessity of finding raw materials that contain low 10Be, our results indicate that it is preferable to select a starting material with a low B concentration. -
C:\Documents and Settings\Alan Smithee\My Documents\MOTM
Rdosdladq1//6Lhmdq`knesgdLnmsg9@bshmnkhsd This month’s featured mineral has many interesting and unusual varieties: While our specimens have well-developed prismatic crystals, which is unusual for actinolite, a fibrous variety is a former ore of asbestos, and a microcrystalline variety is one of the two types of the gemstone jade. Read on! OGXRHB@K OQNODQSHDR 2+ Chemistry: GCa2(Mg,Fe )5Si8O22(OH)2 Basic Calcium Magnesium Iron Silicate (Calcium Magnesium Iron Silicate Hydroxide) Class: Silicates Subclass: Inosilicates (Double-Chain Silicates) Group: Tremolite (Amphibole Group) Crystal System: Monoclinic Crystal Habits: Usually long prismatic with diamond-shaped cross section; also bladed, columnar, acicular, divergent, fibrous (asbestiform), and radiating. A compact, microcrystalline form is known as nephrite jade. Color: Bright-to-dark green, grayish-green, and greenish-black. Luster: Vitreous; silky and pearly on cleavage surfaces. Transparency: Transparent to translucent Streak: Colorless to white Cleavage: Perfect in two directions lengthwise with intersecting cleavage planes. Fracture: Splintery, uneven; fibrous forms are flexible. Hardness: 5.0-6.0, nephrite variety is 6.5. Specific Gravity: 3.0-3.5 Luminescence: None Refractive Index: 1.63-1.66 Distinctive Features and Tests: Best field marks are the prismatic, often-radiating crystal habit and narrow cleavage-intersection angle. Can be confused with wollastonite, which is fluorescent; the tourmaline-group minerals, which lack cleavage; and epidote, which has a broader cleavage angle. Laboratory methods are necessary to differentiate actinolite from tremolite and ferro- actinolite, as explained in the box on Page 3. Dana Classification Number: 66.1.3a.2 M @L D The name “actinolite,” pronounced ack-TIH-no-lite, derives from the Greek aktino, meaning “ray,” a reference to the common radiate habit of its prismatic crystals. -
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. -
Colourless Gemstones
GEMS THE gem DeteCTIVE: COLOURLess gemstONes superseded in the 1970s by a man-made gemstone called cubic zirconia that is still the most popular and common diamond imitation in modern jewellery due to its low cost, high dispersion and good hardness (8.5 on Mohs scale). Another man-made gemstone called synthetic Moissanite was introduced as a diamond simulant in the late 1990s. Although TED A synthetic Moissanite tests positive on a FFILI A diamond tester, it is easily distinguished from diamond by a property called double refraction, detected using a 10x loupe. This property is also displayed by zircon, a natural CCREESH, O’NEILS O’NEILS CCREESH, gemstone with a sub-adamantine lustre. M N N A Complicating the process of identification are treatments that may affect the value of gemstones. For example, a laser may be used to drill down to a dark diamond inclusion and remove it using acid in a process called GE COURTESY OF BREND OF COURTESY GE laser drilling. Also common is fracture filling, ma I where a high refractive-index lead glass is used to fill surface-reaching fractures to make Sparkling, colourless gemstones may People love to assume that their great ALTHOUGH them less visible. Fortunately, both of these appear similar to the naked eye but they grandma’s solitaire engagement ring SYNTHETIC treatments are easily identified using a loupe can vary significantly in identity, rarity contained a natural diamond by virtue MOISSANITE or microscope. TESTS POSITIVE and value. Making such distinctions of its age but they should think again. Some off-coloured diamonds may be ON A DIamOND requires the detective skills of a qualified Synthetically-produced sapphire, spinel and TESTER, IT CAN BE whitened using High Pressure High gemmologist. -
GAO-09-987 International Trade: U.S. Agencies Have Taken Some Steps
United States Government Accountability Office Report to Congressional Committees GAO September 2009 INTERNATIONAL TRADE U.S. Agencies Have Taken Some Steps, but Serious Impediments Remain to Restricting Trade in Burmese Rubies and Jadeite GAO-09-987 September 2009 INTERNATIONAL TRADE Accountability Integrity Reliability U.S. Agencies Have Taken Some Steps, but Serious Highlights Impediments Remain to Restricting Trade in Burmese Highlights of GAO-09-987, a report to Rubies and Jadeite congressional committees Why GAO Did This Study What GAO Found Congress passed the Tom Lantos The Burmese jadeite and ruby trades are very different from one another and Block Burmese JADE Act in 2008 significantly involve China and Thailand. Burmese-origin jadeite is primarily prohibiting the import of Burmese- purchased, processed, and consumed by China. Burmese-origin rubies are origin jadeite, rubies, and related reportedly largely smuggled into Thailand, yielding little revenue to the jewelry and calling for certain Burmese regime, and are significantly processed there. international actions. The act also requires GAO to assess the effectiveness of the U.S. agencies have taken some steps but have not shown that they are implementation of this section of effectively restricting imports of Burmese-origin rubies, jadeite, and related the act. jewelry while allowing imports of non-Burmese-origin goods. Some U.S. jewelry representatives said import restrictions constrain legitimate ruby This report assesses (1) key imports. Agencies published an interim final rule, but DHS has not developed characteristics of the trade of specific audit guidance or conducted any postentry reviews of importers’ Burmese-origin jadeite and rubies; records. In addition, there is little guidance to importers on what constitutes (2) progress agencies have made to verifiable evidence of non-Burmese-origin.