Type Classification of Diamonds
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The World of Pink Diamonds and Identifying Them
GEMOLOGY GEMOLOGY as to what dealers can do to spot them using standard, geologists from Ashton Joint Venture found certain indicator The World of Pink Diamonds inexpensive instruments. The commercial signifcance of minerals (such as ilmenite, chromite, chrome diopside, the various types will also be touched on. and pyrope garnet) in stream-gravel concentrates which indicated the presence of diamond-bearing host rocks. and Identifying Them Impact of Auction Sales Lamproites are special ultrapotassic magnesium-rich In the late 1980s, the public perception surrounding fancy- mantle-derived volcanic rocks with low CaO, Al2O3, Na2O colored diamonds began to change when the 0.95-carat and high K2O. Leucite, glass, K-richterite, K-feldspar and Cr- By Branko Deljanin, Dr Adolf Peretti, ‘Hancock Red’ from Brazil was sold for almost $1 million per spinel are unique to lamproites and are not associated with and Matthias Alessandri carat at a Christie’s auction. This stone was studied by one kimberlites. The diamonds in lamproites are considered to be of the authors (Dr. Adolf Peretti) at that time. Since then, xenocrysts and derived from parts of the lithospheric mantle Dr. Peretti has documented the extreme impact this one that lies above the regions of lamproite genesis. Kimberlites sale has had on subsequent prices and the corresponding are also magmatic rocks but have a different composition recognition of fancy diamonds as a desirable asset class. The and could contain non-Argyle origin pink diamonds. demand for rare colors increased and the media began to play a more active role in showcasing new and previously Impact of Mining Activities unknown such stones. -
New Generations of Boron-Doped Diamond Structures by Delta-Doping Technique for Power Electronics : CVD Growth and Characterization Alexandre Fiori
New generations of boron-doped diamond structures by delta-doping technique for power electronics : CVD growth and characterization Alexandre Fiori To cite this version: Alexandre Fiori. New generations of boron-doped diamond structures by delta-doping technique for power electronics : CVD growth and characterization. Electronics. Université de Grenoble, 2012. English. NNT : 2012GRENI018. tel-00967208v2 HAL Id: tel-00967208 https://tel.archives-ouvertes.fr/tel-00967208v2 Submitted on 28 Jun 2017 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. THÈSE Pour obtenir le grade de DOCTEUR DE L’UNIVERSITÉ DE GRENOBLE Spécialité : Matériaux, Mécanique, Génie civil, Electrochimie Arrêté ministériel : 7 août 2006 Présentée par Alexandre FIORI Thèse dirigée par Franck Omnès et codirigée par Julien Pernot préparée au sein de l’institut Néel au CNRS à Grenoble dans l'École Doctorale I-MEP2 : Ingénierie – Matériaux, mécanique, Environnement, Energétique, Procédés, Production Nouvelles générations de structures en diamant dopé au bore par technique de delta-dopage pour l’électronique de puissance : croissance par CVD et caractérisation Thèse soutenue publiquement le 24 octobre 2012, devant le jury composé de : M. Christophe VALLEE Professeur, Université de Grenoble, Président M. Ken HAENEN Professeur, Université de Hasselt, Rapporteur M. -
Blue Sapphire Engagement Ring, RG-2817U Dramatic Color And
Blue Sapphire Engagement Ring, RG-2817u Dramatic color and unusual elegance come together in this vintage style blue sapphire engagement ring. The 18k white gold band of this engagement ring is set along the shoulders and shank with a collection of seventy-four round brilliant cut diamonds that total 0.52 carats. Eight of these diamonds, four on each side, are arranged in a floral design. The diamond flowers flank a bewitching blue sapphire at the center. This is a vintage style (new) blue sapphire engagement ring. Options None Item # rg2817u Metal 18k white gold Weight in grams 4.6 Special characteristics A matching band is available and may be purchased separately. Please see item RG-2817wb. Condition New Diamond cut or shape round brilliant Diamond carat weight 0.52 Diamond mm measurements 1.4-0.9 Diamond color G-H Diamond clarity VS1 Diamond # of stones 74 Gemstone name Natural Corundum (sapphire) Gemstone cut or shape round faceted mixed cut Gemstone carat weight 1.05 Gemstone type Type II Gemstone clarity VS Gemstone hue very very slightly greenish blue Gemstone tone 4-Medium Light Gemstone saturation 4-Moderately Strong Gemstone # of stones 1 Top of ring length (N-S) 6.75 mm [0.26 in] Width of shank at shoulders 4.85 mm [0.19 in] Width of shank at base 2.25 mm [0.09 in] Ring height above finger 6.9 mm [0.27 in] Other ring info For new rings like this one, the gram weight, diamond and gemstone carat weights, color, and clarity, as well as other jewelry details, may vary from the specifications shown on this page, but are similar in quality. -
PGDNET Education
ALCHEMY ABOVE EARTH ABOUT PURE GROWN DIAMONDS Conceived in 2014, Pure Grown Diamonds (PGD) has been growing steadily in the USA’s big and small multi-brand jewelry retail stores. It distinguishes itself sharply in the very source of the jewels – they are grown above the earth. A state of the art facility uses cutting edge technology in an environment that mimics nature below the earth. PGD is built on an intensely sharp competitive advantage – ability to produce very high quality Type IIa diamonds that can go upto 5 carat stone in cut and polished form. Since these diamonds are sustainably grown above earth with fair production practices, they are ethical in the truest sense and leave a significantly smaller carbon footprint when compared to mined diamonds. OUR PRODUCT Pure Grown Diamonds are grown above the earth using cutting-edge technology that allows consistent production of high quality, stunning Type IIa diamonds with unmatched brilliance. Our diamonds range go up to 5 carats, making them the perfect representation of the unique relationship the couple shares. We offer a variety of loose diamonds and finished jewelry. What are Type IIa diamonds? Diamond is 99.95 percent carbon. The other 0.05 percent can include one or more trace elements, or impurities, which are atoms that aren’t part of the diamond’s essential chemistry. Diamond type is a method of scientifically classifying diamonds, both grown and mined, by the level and type of their chemical impurities. Extremely rare in nature, Type IIa diamonds account for less than 2% of the world’s mined diamonds. -
A Defect Study and Classification of Brown Diamonds with Deformation
minerals Article A Defect Study and Classification of Brown Diamonds with Deformation-Related Color Thomas Hainschwang 1,*, Franck Notari 2 and Gianna Pamies 1 1 GGTL Laboratories, Gnetsch 42, 9496 Balzers, Liechtenstein; [email protected] 2 GGTL Laboratories, 2 bis route des Jeunes, 1227 Geneva, Switzerland; [email protected] * Correspondence: [email protected]; Tel.: +423-262-24-64 Received: 3 September 2020; Accepted: 7 October 2020; Published: 12 October 2020 Abstract: For this study, the properties of a large sample of various types of brown diamonds with a deformation-related (referred to as “DR” in this work) color were studied to properly characterize and classify such diamonds, and to compare them to pink to purple to red diamonds. The acquisition of low temperature NIR spectra for a large range of brown diamonds and photoexcitation studies combined with various treatment experiments have opened new windows into certain defect characteristics of brown diamonds, such as the amber centers and naturally occurring H1b and H1c centers. It was determined that the amber centers (referred to as “AC” in this work) exhibit rather variable behaviors to annealing and photoexcitation; the annealing temperature of these defects were determined to 1 range from 1150 to >1850 ◦C and it was found that the 4063 cm− AC was the precursor defect of many other ACs. It is suggested that the amber centers in diamonds that contain at least some C centers are essentially identical to the ones seen in diamonds without C centers, but that they likely have a negative charge. -
Ruby and Diamond Engagement Ring, RG-2408 the 18K White Gold Band of This Ruby Engagement Ring Is Set Three-Quarters of The
Ruby and Diamond Engagement Ring, RG-2408 The 18k white gold band of this ruby engagement ring is set three-quarters of the way around with sixty round full cut diamonds weighing 0.77 carats. The diamonds are dazzling against the brilliant color of the ruby. This round faceted mixed cut ruby weighs 1.05 carats. This is a new ruby and diamond engagement ring. Options None Item # rg2408 Metal 18 karat white gold Weight in grams 4.06 Condition New Diamond cut or shape round full cut Diamond carat weight 0.77 Diamond mm measurements 1.0 to 2.7 Diamond color G and H Diamond clarity VVS1 to VS2 Diamond # of stones 60 Gemstone name Natural Corundum (Ruby) Gemstone cut or shape round, faceted mixed cut Gemstone carat weight 1.053 Gemstone mm measurements 6.26 - 6.31 x 3.32 Gemstone type Type II Gemstone clarity SI2 Gemstone hue very, very slightly purplish red Gemstone tone 4.-5 Gemstone saturation 4-Moderately Strong Gemstone # of stones 1 Top of ring length (N-S) 6.20 mm [0.24 in] Top of ring width (E-W) 17.78 mm [0.69 in] Width of shank at shoulders 2.48 mm [0.10 in] Width of shank at base 2.37 mm [0.09 in] Ring height above finger 7.53 mm [0.29 in] Ring Size 6.5 Important Jewelry Information Each antique and vintage jewelry piece is sent off site to be evaluated by an appraiser who is not a Topazery employee and who has earned the GIA Graduate Gemologist diploma as well as the title of AGS Certified Gemologist Appraiser. -
Making Measurements and Using Testing Tools for Specific Properties of Gem Materials Gemstones Are Very Small and Hold Concentra
Making Measurements and Using Testing Tools for Specific Properties of Gem Materials Gemstones are very small and hold concentrated wealth. To correctly identify a cut gemstone may in some instances be much harder than trying to identify a piece of rough material. Many gemstone crystals in rough materials have characteristic crystal shape, cleavage, or fracture, but often you can’t see these properties in cut materials — color, density, luster, reflectivity, heat conduction, magnification, and optical properties are ways to look at cut stones non-destructively and identify them. In this lab we will work with some larger stones and make measurements, Such measurements will be applied to specific stones when we learn gems in a systematic way (as we did with minerals) doing individual groups in labs devoted to them. But for now our goal is to learn the instrumentation, including the names and the parts of the instruments. Importantly, we will learn how to handle the testing equipment in a consistent and practical way so as to avoid any damage to either gemstones or to the testing equipment. Measuring gemstones includes their dimensions, weight (or mass), and describing their color, etc. It is sometimes important in their identification as well, a too heavy feeling gem may not be what it appears to be! Weighing Gemstones First 1 gram is 1/1000 (one one thousandth of a kilogram). The kilogram is defined by a piece of metal held in a laboratory in France. However, a gram is also defined as a milliliter of water at 4oC. These measurement units are part of the International System of Units (abbreviated SI from French: Système international d'unités). -
Winter 1998 Gems & Gemology
WINTER 1998 VOLUME 34 NO. 4 TABLE OF CONTENTS 243 LETTERS FEATURE ARTICLES 246 Characterizing Natural-Color Type IIb Blue Diamonds John M. King, Thomas M. Moses, James E. Shigley, Christopher M. Welbourn, Simon C. Lawson, and Martin Cooper pg. 247 270 Fingerprinting of Two Diamonds Cut from the Same Rough Ichiro Sunagawa, Toshikazu Yasuda, and Hideaki Fukushima NOTES AND NEW TECHNIQUES 281 Barite Inclusions in Fluorite John I. Koivula and Shane Elen pg. 271 REGULAR FEATURES 284 Gem Trade Lab Notes 290 Gem News 303 Book Reviews 306 Gemological Abstracts 314 1998 Index pg. 281 pg. 298 ABOUT THE COVER: Blue diamonds are among the rarest and most highly valued of gemstones. The lead article in this issue examines the history, sources, and gemological characteristics of these diamonds, as well as their distinctive color appearance. Rela- tionships between their color, clarity, and other properties were derived from hundreds of samples—including such famous blue diamonds as the Hope and the Blue Heart (or Unzue Blue)—that were studied at the GIA Gem Trade Laboratory over the past several years. The diamonds shown here range from 0.69 to 2.03 ct. Photo © Harold & Erica Van Pelt––Photographers, Los Angeles, California. Color separations for Gems & Gemology are by Pacific Color, Carlsbad, California. Printing is by Fry Communications, Inc., Mechanicsburg, Pennsylvania. © 1998 Gemological Institute of America All rights reserved. ISSN 0016-626X GIA “Cut” Report Flawed? The long-awaited GIA report on the ray-tracing analysis of round brilliant diamonds appeared in the Fall 1998 Gems & Gemology (“Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance,” by T. -
Winter 2009 Gems & Gemology
G EMS & G VOLUME XLV WINTER 2009 EMOLOGY W INTER 2009 P AGES 235–312 Ruby-Sapphire Review V Nanocut Plasma-Etched Diamonds OLUME Chrysoprase from Tanzania 45 N Demantoid from Italy O. 4 THE QUARTERLY JOURNAL OF THE GEMOLOGICAL INSTITUTE OF AMERICA EXPERTISE THAT SPREADS CONFIDENCE. Because Public Education AROUND THE WORLD AND AROUND THE CLOCK. Happens at the Counter. ISRAEL 5:00 PM GIA launches Retailer Support Kit and website Cutter checks parameters online with GIA Facetware® Cut Estimator. NEW YORK 10:00 AM GIA Master Color Comparison Diamonds confirm color quality of a fancy yellow. CARLSBAD 7:00 AM MUMBAI 7:30 PM Laboratory technicians calibrate Staff gemologist submits new findings on measurement devices before coated diamonds to GIA global database. the day’s production begins. HONG KONG 10:00 PM Wholesaler views grading results and requests additional services online at My Laboratory. JOHANNESBURG 5:00 PM Diamond graders inscribe a diamond and issue a GIA Diamond Dossier® A $97.00 value, shipping and handling extra. All across the planet, GIA labs and gemological reports are creating a common language for accurate, unbiased gemstone GIA’s Retailer Support Kit has been developed to help evaluation. From convenient locations in major gem centers, to frontline detection of emerging treatments and synthetics, to online services that include ordering, tracking, and report previews — GIA is pioneering the technology, tools and talent sales associates educate the public about diamonds, that not only ensure expert service, but also advance the public trust in gems and jewelry worldwide. the 4Cs, and thoroughly explain a GIA grading report. -
Investing in Colored Diamonds from Diamond Investment Dealers
BENEFITS OF INVESTING IN COLORED DIAMONDS FROM DIAMOND INVESTMENT DEALERS When investing in diamonds you need an ad- ly appreciated in value. Over the last decade, visor who has the depth and breadth of knowl- Argyle pink diamonds have consistently bro- edge in investment grade diamonds. Rare ken records on the global auction market, Diamond Investor provides seamless access demonstrating the robust nature of the dia- for savvy investors. We focus exclusively on mond market and the unceasing international natural fancy-colored diamonds and are staffed demand. Christies auctions have surpassed by experts in every facet of the diamond mar- records the last few years for both the most ket. This level of experience and expertise not expensive investment grade diamonds and only gives us greater understanding of the di- the highest price per carat. In April 2014, Chris- amond market, but also gives us access to a ties auctioned top quality, fancy pink, blue professional global network of investors, col- and yellow diamonds with prices exceeding of lectors and industry specialists including the $1 to $2 million per carat, leading Christies most sought after gemologists and diamond to declare 2014 the year of the colored dia- cutters in the world. mond. Rahul Kadakia, Head of Christies New York, states, At a time when other investments have suf- fered unparalleled chaos and uncertainty, “A colorless D-grade diamond at auction will make about $150,000 a carat, while a pink natural fancy-colored diamonds have steadi- fancy-colored diamond will make $1.5 million a carat, 10 times the price.” He also stated, “This is where the market is. -
Gem Diamonds: Causes of Colors
New Diamond and Frontier Carbon Technology Vol. 17, No. 3 2007 MYU Tokyo NDFCT 536 Gem Diamonds: Causes of Colors Hiroshi Kitawaki Gemmological Association of All Japan, Ueno 5-25-11, Taito-ku, Tokyo 110-0005, Japan (Received 9 May 2007; accepted 1 August 2007) Key words: gem, natural diamond, color, treatment Diamonds for gem use are colorless in general, but some stones with bright colors are highly valued as fancy color diamonds. The body color of diamond depends on the concentration of nitrogen and the form of aggregation. Structural defects and vacancy bonding may also cause color centers. Furthermore, plastic deformation may bring DERXWFRORU5HFHQWO\DUWL¿FLDOFRORULQJWRLQWHQWLRQDOO\SURGXFH³IDQF\FRORU´VWRQHV has been carried out on a commercial basis. The combined process of electron beam irradiation with annealing and the high-pressure high-temperature (HPHT) process are quite common treatment techniques today. Leading gem laboratories around the world are currently working on these tasks to establish techniques, with a few exceptions, for revealing the origin of the color of the diamond. 1. Introduction Diamond quality as a gemstone is generally graded by the four Cs. Diamonds of a FHUWDLQFDUDWZLWK¿QHFXWDQGFODULW\JUDGHVYDU\ODUJHO\LQYDOXHDFFRUGLQJWRWKHLUFRORU $SHUIHFWGLDPRQGLVWKHRUHWLFDOO\FRORUOHVVWUDQVSDUHQWDQGVKRZVQRÀXRUHVFHQFH to UV light. In nature, however, even an almost perfect crystal is very rare; hence, it is highly evaluated. Commercially available gem diamonds often show a slightly yellow tint that is derived from a nitrogen-related defect. As the yellow tint becomes more intense, the value of a stone is generally lowered, but other colors such as pink, green or blue are valued for the color itself as fancy color diamonds, and there is a market for such diamonds. -
Diamond Buying Guide
SELECTING A DIAMOND PROTECT YOUR DIAMOND OUR GIA GEMOLOGIST DISTINCT ELEGANT TIMELESS HOW A DIAMOND IS GRADED TIPS TO SAFEGUARD YOUR DIAMOND VICTORIA KING, GIA GG Not all diamonds are created equal. Every • Choose a secure setting. Vicki is a graduate of the prestigious diamond is unique. Diamonds come in • Keep your diamond clean. Gemological Institute of America. She is many sizes, shapes, colors, and with various a highly skilled gemologist who has the • Place your diamond in a jewelry box or other internal characteristics. At King Jewelers, technical knowledge needed to grade and safe place when you are not wearing it. we use the grading system developed by the determine diamond quality as well as the Gemological Institute of America in the 1950’s • We recommend getting a professional cleaning value of other gemstones. Vicki brings which established the use of four important and inspection every 6 months. more than 40 years of skill and expertise factors to describe and classify diamonds: • Have your diamond appraised and insured. to her work, and operates a full service Clarity, Color, Cut, and Carat Weight. gem laboratory on the premises. “We guarantee the grading of your Your diamond may be The distinguished GIA GG designation is diamond’s color, clarity and carat the most expensive stone instantly recognized around the world as weight to be at least as good as you ever buy. Most likely, the mark of a senior professional in the Understanding we promised you and to be in you will wear your diamond every day so jewelry industry. accordance with the guidelines the odds are high that you could misplace or the Value of of the Gemological Institute even lose you diamond.