Volume 35 / No. 2 / 2016
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Rhodochrosite Gems Unstable Colouration of Padparadscha-Like
Volume 36 / No. 4 / 2018 Effect of Blue Fluorescence on the Colour Appearance of Diamonds Rhodochrosite Gems The Hope Diamond Unstable Colouration of in London Padparadscha-like Sapphires Volume 36 / No. 4 / 2018 Cover photo: Rhodochrosite is prized as both mineral specimens and faceted stones, which are represented here by ‘The Snail’ (5.5 × 8.6 cm, COLUMNS from N’Chwaning, South Africa) and a 40.14 ct square-cut gemstone from the Sweet Home mine, Colorado, USA. For more on rhodochrosite, see What’s New 275 the article on pp. 332–345 of this issue. Specimens courtesy of Bill Larson J-Smart | SciAps Handheld (Pala International/The Collector, Fallbrook, California, USA); photo by LIBS Unit | SYNTHdetect XL | Ben DeCamp. Bursztynisko, The Amber Magazine | CIBJO 2018 Special Reports | De Beers Diamond ARTICLES Insight Report 2018 | Diamonds — Source to Use 2018 The Effect of Blue Fluorescence on the Colour 298 Proceedings | Gem Testing Appearance of Round-Brilliant-Cut Diamonds Laboratory (Jaipur, India) By Marleen Bouman, Ans Anthonis, John Chapman, Newsletter | IMA List of Gem Stefan Smans and Katrien De Corte Materials Updated | Journal of Jewellery Research | ‘The Curse Out of the Blue: The Hope Diamond in London 316 of the Hope Diamond’ Podcast | By Jack M. Ogden New Diamond Museum in Antwerp Rhodochrosite Gems: Properties and Provenance 332 278 By J. C. (Hanco) Zwaan, Regina Mertz-Kraus, Nathan D. Renfro, Shane F. McClure and Brendan M. Laurs Unstable Colouration of Padparadscha-like Sapphires 346 By Michael S. Krzemnicki, Alexander Klumb and Judith Braun 323 333 © DIVA, Antwerp Home of Diamonds Gem Notes 280 W. -
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. -
Phase Evolution of Ancient and Historical Ceramics
EMU Notes in Mineralogy, Vol. 20 (2019), Chapter 6, 233–281 The struggle between thermodynamics and kinetics: Phase evolution of ancient and historical ceramics 1 2 ROBERT B. HEIMANN and MARINO MAGGETTI 1Am Stadtpark 2A, D-02826 Go¨rlitz, Germany [email protected] 2University of Fribourg, Department of Geosciences, Earth Sciences, Chemin du Muse´e 6, CH-1700 Fribourg, Switzerland [email protected] This contribution is dedicated to the memory of Professor Ursula Martius Franklin, a true pioneer of archaeometric research, who passed away at her home in Toronto on July 22, 2016, at the age of 94. Making ceramics by firing of clay is essentially a reversal of the natural weathering process of rocks. Millennia ago, potters invented simple pyrotechnologies to recombine the chemical compounds once separated by weathering in order to obtain what is more or less a rock-like product shaped and decorated according to need and preference. Whereas Nature reconsolidates clays by long-term diagenetic or metamorphic transformation processes, potters exploit a ‘short-cut’ of these processes that affects the state of equilibrium of the system being transformed thermally. This ‘short-cut’ is thought to be akin to the development of mineral-reaction textures resulting from disequilibria established during rapidly heated pyrometamorphic events (Grapes, 2006) involving contact aureoles or reactions with xenoliths. In contrast to most naturally consolidated clays, the solidified rock-like ceramic material inherits non-equilibrium and statistical states best described as ‘frozen-in’. The more or less high temperatures applied to clays during ceramic firing result in a distinct state of sintering that is dependent on the firing temperature, the duration of firing, the firing atmosphere, and the composition and grain-size distribution of the clay. -
The Wittelsbach-Graff and Hope Diamonds: Not Cut from the Same Rough
THE WITTELSBACH-GRAFF AND HOPE DIAMONDS: NOT CUT FROM THE SAME ROUGH Eloïse Gaillou, Wuyi Wang, Jeffrey E. Post, John M. King, James E. Butler, Alan T. Collins, and Thomas M. Moses Two historic blue diamonds, the Hope and the Wittelsbach-Graff, appeared together for the first time at the Smithsonian Institution in 2010. Both diamonds were apparently purchased in India in the 17th century and later belonged to European royalty. In addition to the parallels in their histo- ries, their comparable color and bright, long-lasting orange-red phosphorescence have led to speculation that these two diamonds might have come from the same piece of rough. Although the diamonds are similar spectroscopically, their dislocation patterns observed with the DiamondView differ in scale and texture, and they do not show the same internal strain features. The results indicate that the two diamonds did not originate from the same crystal, though they likely experienced similar geologic histories. he earliest records of the famous Hope and Adornment (Toison d’Or de la Parure de Couleur) in Wittelsbach-Graff diamonds (figure 1) show 1749, but was stolen in 1792 during the French T them in the possession of prominent Revolution. Twenty years later, a 45.52 ct blue dia- European royal families in the mid-17th century. mond appeared for sale in London and eventually They were undoubtedly mined in India, the world’s became part of the collection of Henry Philip Hope. only commercial source of diamonds at that time. Recent computer modeling studies have established The original ancestor of the Hope diamond was that the Hope diamond was cut from the French an approximately 115 ct stone (the Tavernier Blue) Blue, presumably to disguise its identity after the that Jean-Baptiste Tavernier sold to Louis XIV of theft (Attaway, 2005; Farges et al., 2009; Sucher et France in 1668. -
The Anjahamiary Pegmatite, Fort Dauphin Area, Madagascar
The Anjahamiary pegmatite, Fort Dauphin area, Madagascar Federico Pezzotta* & Marc Jobin** * Museo Civico di Storia Naturale, Corso Venezia 55, I-20121 Milano, Italy. ** SOMEMA, BP 6018, Antananarivo 101, Madagascar. E-mail:<[email protected]> 21 February, 2003 INTRODUCTION Madagascar is among the most important areas in the world for the production, mainly in the past, of tourmaline (elbaite and liddicoatite) gemstones and mineral specimens. A large literature database documents the presence of a number of pegmatites rich in elbaite and liddicoatite. The pegmatites are mainly concentrated in central Madagascar, in a region including, from north to south, the areas of Tsiroanomandidy, Itasy, Antsirabe-Betafo, Ambositra, Ambatofinandrahana, Mandosonoro, Ikalamavony, Fenoarivo and Fianarantsoa (e.g. Pezzotta, 2001). In general, outside this large area, elbaite-liddicoatite-bearing pegmatites are rare and only minor discoveries have been made in the past. Nevertheless, some recent work made by the Malagasy company SOMEMEA, discovered a great potential for elbaite-liddicoatite gemstones and mineral specimens in a large, unusual pegmatite (the Anjahamiary pegmatite), hosted in high- metamorphic terrains. The Anjahamiary pegmatite lies in the Fort Dauphin (Tôlanaro) area, close to the southern coast of Madagascar. This paper reports a general description of this locality, and some preliminary results of the analytical studies of the accessory minerals collected at the mine. Among the most important analytical results is the presence of gemmy blue liddicoatite crystals with a very high Ca content, indicating the presence in this tourmaline crystal of composition near the liddicoatite end-member. LOCATION AND ACCESS The Anjahamiary pegmatite is located about 70 km NW of the town of Fort Dauphin (Tôlanaro) (Fig. -
Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique
GIT GEMSTONE UPDATE Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique By GIT-Gem testing laboratory 11 May 2016 Introduction In March 2016, a group of Thai gem dealer led by Mr. Pichit Nilprapaporn paid a visit to the GIT and informed us about a new garnet deposit in Mozambique, that was discovered near the western border with Zimbabwe. They also displayed a large parcel of rough and a few cut stones claimed to be the material found in this new deposit (Figure 1). According to the stone’s owner, these garnet specimens were unearthed from an unconsolidated sediment layer, just a few meters below ground surface. This brief report is our preliminary investigation on the interesting vivid purple garnet from the new deposit in Mozambique. Figure 1: Mr. Pichit Nilprapaporn (center), the stone’s owner, showing a large parcel of purple gar- net roughs claimed to be from a new deposit in Mozambique to the GIT director (left). The Gem and Jewelry Institute of Thailand (Public Organization) 140, 140/1-3, 140/5 ITF-Tower Building. 1st - 4th and 6th Floor,Silom Road, Suriyawong, Bangrak, Bangkok 10500 Thailand Tel: +66 2634 4999 Fax: +66 2634 4970; Web: http://www.git.or.th; E-mail: [email protected] 11 May, 2016 Preliminary Investigation of Purple Garnet from a New Deposit in Mozambique 2 Samples and Testing Procedure The stone’s owners donated some specimens (one 6.10 ct oval-facetted stone and 13 rough samples weighing from 3.83 to 9.43 cts) to the GIT Gem Testing Laboratory for studying. -
Mineral Processing
Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19 -
Analytical Methods to Differentiate Romanian Amber and Baltic Amber for Archaeological Applications
Cent. Eur. J. Chem. • 7(3) • 2009 • 560-568 DOI: 10.2478/s11532-009-0053-8 Central European Journal of Chemistry Analytical methods to differentiate Romanian amber and Baltic amber for archaeological applications Research Article Eugenia D. Teodor1*, Simona C. Liţescu1, Antonela Neacşu2, Georgiana Truică1 Camelia Albu1 1 National Institute for Biological Sciences, Centre of Bioanalysis, Bucharest, 060031, Romania 2 University of Bucharest, Faculty of Geology and Geophysics, Bucharest, 010041, Romania Received 27 August 2008; Accepted 02 March 2009 Abstract: The study aims to establish several definite criteria which will differentiate Romanian amber and Baltic amber to certify the local or Baltic origin of the materials found in archaeological sites on the Romanian territory, by using light microscopy and performing analytical methods, such as Fourier transform infrared spectroscopy-variable angle reflectance and liquid chromatography with mass spectrometry detection. Experiments especially by Fourier transformed infrared spectroscopy, were applied to a wide range of samples with controlled origin. The methods were optimised and resulted in premises to apply the techniques to analysis of the archaeological material. Keywords: Romanian amber • FTIR-VAR • LC-MS • Light microscopy © Versita Warsaw and Springer-Verlag Berlin Heidelberg. 1. Introduction (Oligocene). The resin-bearing strata are intercalated within the lower and medium part of the lower Kliwa Amber is a fossil resin originating from different types sandstone (0.20-1.40 m). They consist of siliceous clay of Conifers and certain flowering trees, especially in hot (0.20-1.40 m) always containing thin intercalations of climates. From the mineralogical point of view amber bituminous shales (2-5 cm) and of preanthracite coal could be considered a mineraloid. -
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. -
Origin of Color in Cuprian Elbaite from Sflo Jos6 De Batalha, Paraiba, Brazil
American Mineralogist, Volume 76, pages 1479-1484, I99I Origin of color in cuprian elbaite from Sflo Jos6 de Batalha, Paraiba, Brazil Gnoncn R. Rosslvr,tN Division of Geology and Planetary Sciences,l7O-25, California Institute of Technology, Pasadena,California 9l125, U.S.A Evrvrm.luel FnrrscH, J,lvrns E. Srncr.Bv GIA Research,Gemological Institute of America, 1660 Stewart Street,Santa Monica, California 90404-4088, U.S.A. Ansrn-q.cr Gem-quality elbaite from Paraiba, Brazil, containing up to 1.4 wt0i6Cu has been char- acterizedusing optical spectroscopyand crystal chemistry. The optical absorption spectra of Cu2t in these tourmalines consist of two bands with maxima in the 695- to 940-nm region that are more intense in the E I c direction. The vivid yellowish green to blue- greencolors of theseelbaite samplesarise primarily from Cu2*and are modified to violet- blue and violet hues by increasingabsorptions from Mn3*. IwrnooucrtoN in a small, decomposed granitic pegmatite (formerly quartz, The color of elbaite has hen extensively investigated. prospectedfor manganotantalite).The associated Most colors are determined by small amounts of transi- altered feldspar, and lepidolite have not been character- tion elements(Dietrich, 1985).In particular, blue to green ized. Most of the tourmalines occur as crystal fragments colors have been attributed to various processesinvolv- weighing less than a g.ram,although pieceslarge enough ing both Fe2*and Fe3*ions (Mattson and Rossman, 1987) to produce facetedgemstones up to 33 carats(6.6 g) have and Fe2*- Tia* chargetransfer (Mattson, as cited in Die- been found. In rare instances, small crystals are recov- trich, 1985, p. -
Preprint American Mineralogist 407
This is a preprint, the final version is subject to change, of the American Mineralogist (MSA) Cite as Authors (Year) Title. American Mineralogist, in press. (DOI will not work until issue is live.) DOI: http://dx.doi.org/10.2138/am.2012.4189 7/11 1 Semi-quantitative determination of the Fe/Mg ratio in synthetic cordierite using 2 Raman spectroscopy 3 REVISION 1 4 Authors: Udo Haefeker1, Reinhard Kaindl2, Peter Tropper1 5 6 1Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 7 Innsbruck, Austria. 8 E-mail: [email protected] 9 2Present address: MATERIALS – Institute for Surface Technologies and Photonics, 10 Functional Surfaces, JOANNEUM RESEARCH Forschungsgesellschaft mbH, 11 Leobner Straße 94, A-8712 Niklasdorf, Austria. 12 13 ABSTRACT 14 Investigations of H2O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe = 0-1) 15 with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg 16 ratio and the position of certain Raman peaks. In the range between 100 and 1250 17 cm-1 all peaks except for three peaks shift towards lower wavenumbers with 18 increasing XFe as a consequence of the substitution of the lighter Mg by the heavier 19 Fe atom on the octahedral sites and the associated structural changes. Selected 20 medium and strong peaks show a shift of 5 to 13 cm-1, respectively. Based on recent 21 quantum-mechanicalPreprint calculations American (Kaindl et al. 2011) Mineralogist these shifts can be attributed to 22 specific vibrational modes in the cordierite structure, thus showing that the Mg-Fe 23 exchange affects the vibrational modes of tetrahedral, octahedral and mixed sites. -
Brief Report Acta Palaeontologica Polonica 59 (4): 927–929, 2014
Brief report Acta Palaeontologica Polonica 59 (4): 927–929, 2014 Estimating fossil ant species richness in Eocene Baltic amber DAVID PENNEY and RICHARD F. PREZIOSI Fossil insects in amber are often preserved with life-like fidel- (Wichard and Grevin 2009), has approximately 3500 species of ity and provide a unique insight to forest ecosystems of the arthropods described from it (Weitschat and Wichard 2010), and geological past. Baltic amber has been studied for more than is still being extracted from the ground in considerable quanti- 300 years but despite the large number of described fossil ties. For example, it has been estimated that approximately 510 species (ca. 3500 arthropods) and abundance of fossil mate- tonnes of amber were extracted in the Baltic region during the rial, few attempts have been made to try and quantify sta- year 2000 and that approximately two million (a very crude tistically how well we understand the palaeodiversity of this estimate) new inclusions from Baltic amber alone should be remarkable Fossil-Lagerstätte. Indeed, diversity estimation available for study each year (e.g., Clark 2010). Indeed, Klebs is a relatively immature field in palaeontology. Ants (Hyme- recognized the need for quantifying the palaeodiversity of am- noptera: Formicidae) are a common component of the amber ber inclusions at the turn of the twentieth century (Klebs 1910). palaeobiota, with more than 100 described species represent- Klebs (1910) investigated an unsorted Baltic amber sam- ing approximately 5% of all inclusions encountered. Here ple of 200 kg directly from the mine and documented a total we apply quantitative statistical species richness estimation of 13 877 inclusions, but these were identified only to order.