DIAMOND Natural Colorless Type Iab Diamond with Silicon-Vacancy
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A Preliminary Study on the Interfacial Strength of Red Abalone
University of Vermont ScholarWorks @ UVM Graduate College Dissertations and Theses Dissertations and Theses 2016 A Preliminary Study On The nI terfacial Strength Of Red Abalone Saleh Jaman Alghamdi University of Vermont Follow this and additional works at: https://scholarworks.uvm.edu/graddis Part of the Civil Engineering Commons Recommended Citation Alghamdi, Saleh Jaman, "A Preliminary Study On The nI terfacial Strength Of Red Abalone" (2016). Graduate College Dissertations and Theses. 633. https://scholarworks.uvm.edu/graddis/633 This Thesis is brought to you for free and open access by the Dissertations and Theses at ScholarWorks @ UVM. It has been accepted for inclusion in Graduate College Dissertations and Theses by an authorized administrator of ScholarWorks @ UVM. For more information, please contact [email protected]. A PRELIMINARY STUDY ON THE INTERFACIAL STRENGTH OF RED ABALONE A Thesis Presented by Saleh J Alghamdi to The Faculty of the Graduate College of The University of Vermont In Partial Fulfillment of the Requirements for the Degree of Master of Science Specializing in Civil Engineering October, 2016 Defense Date: June 14, 2016 Thesis Examination Committee: Ting Tan, Ph.D, Advisor Jie Yang, Ph.D., Chairperson George Pinder, Ph.D. Cynthia J. Forehand, Ph.D., Dean of the Graduate College Abstract Nacre is a hierarchical material found within the tough shells of red abalone. Despite being composed of calcium carbonate, nacre exhibits remarkable mechanical properties resulting from the nanoscale brick-and-mortar structure made from aragonite polygons. The objective of this research is to elucidate the toughening mechanisms associated with the interfacial resistance of red abalone. -
Pearls and Organic Gemstones
Pearls and Organic Gemstones INTRODUCTION Pearls were probably the first discovered gems of significance. Because they need no cutting or treatment to enhance their beauty and are rare natural occurrences, they have most likely always been highly esteemed. Organic gemstones are anything created by living processes. We have looked at amber in the past, but bone, teeth (such as ivory), and shells all have some value and are used today as gemstones. Pearls in General A pearl is grown by a mollusk (a bivalve such as a clam, oyster, or mussel or snail [single shell = valve]) in response to an irritant. Bivalves (two shelled mollusks) that secrete pearls live in both fresh‐ and saltwater. The irritant in most cases is a parasite (though it could be a grain of sand or other object). The parasite, a worm or other creature, is walled off by a secretion of calcium carbonate and protein. The calcium carbonate is the same as the inorganic material that makes stalactites in caves, and the protein is called conchiolin. The combination of these two substances (calcium carbonate and protein) makes the pearl's nacre (Nacre is also called mother of pearl). The nacre is a lustrous deposit around the irritant and forms concentric layers (overlapping circles). Many concentric layers of nacre build up over a period of a few years creating a pearl. The internal pattern is much like that seen in a jawbreaker. The layers create a sheen or luster that has iridescence and is described as both pearly luster and if colors of the rainbow are present, the pearl's orient. -
Colored Gemstones Cultured Pearls
Cultured Pearls Colored Gemstones Diamond Council of America ©2016 Cultured Pearls In This Lesson: •A World Apart • Pearl Traditions • Natural Pearls • Cultured Pearls •Value Factors •Product Highlights • Culturing Sales A WORLD APART In Lesson 1 you learned that any kind of gem except diamond is considered a colored gem. Although pearls are included in that broad classification, they really belong to a world apart. Most customers recognize this instinctively, sensing a special appeal about pearls. There are several themes you can use in a sales presenta- tion to evoke or enhance pearl’s separate place in the gem kingdom: • Pearls are born in water. This intuitive contrast with other gems, which are dug from the ground, gives pearls an aura of gentleness, freshness, and fluid grace. • Pearls originate from life. While most gems are minerals produced by inanimate geology, pearls are organic. They come from living beings. Much of pearls’ mystique arises from this connection. • Pearls possess a beauty that’s all their own. Most gems depend on cutting or carving to reveal their charms, but pearls emerge gleaming from their shells. Cultured pearls are born in water and originate from living organisms. They Though certain factors of pearl value are comparable are natural in their beauty and classic to those of other gems, key considerations are unique. as a gem. Colored Gemstones 5 1 Cultured Pearls Cultured pearls are modern forms of a classic gem. They ® combine Nature’s creative power with human art and JA SPC SKILLS If you’re participating in the JA® science. You could even say that cultured pearls show how Sales Professional Certification people can work with the environment to make age-old Program™, this lesson presents infor- mation related to the following Skill beauty available now, and for future generations as well. -
Graphene – Diamond Nanomaterials: a Status Quo Review
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 29 July 2021 doi:10.20944/preprints202107.0647.v1 Article Graphene – diamond nanomaterials: a status quo review 1 Jana Vejpravová ,* 1 Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic. * Correspondence: JV, [email protected] Abstract: Carbon nanomaterials with a different character of the chemical bond – graphene (sp2) and nanodiamond (sp3) are the building bricks for a new class of all-carbon hybrid nanomaterials, where the two different carbon networks with the sp3 and sp2 hybridization coexist, interact and even transform into one another. The unique electronic, mechanical, and chemical properties of the two border nanoallotropes of carbon ensure the immense application potential and versatility of these all-carbon graphene – diamond nanomaterials. The review gives an overview of the current state of the art of graphene – diamond nanomaterials, including their composites, heterojunctions, and other hybrids for sensing, electronic, energy storage, and other applications. Also, the graphene- to-diamond and diamond-to-graphene transformations at the nanoscale, essential for innovative fabrication, and stability and chemical reactivity assessment are discussed based on extensive theo- retical, computational, and experimental studies. Keywords: graphene; diamond; nanodiamond; diamane; graphene-diamond nanomaterials; all car- bon materials; electrochemistry; mechanochemistry; sensor; supercapacitor; -
X-Ray Topographic Investigation of Diamond Anvils for High Pressure Generation - Correlation Between Defects and Early Failure
X-ray topographic investigation of diamond anvils for high pressure generation - Correlation between defects and early failure Dewaele A. and Loubeyre P. CEA/DPTA, BP12, 91680 Bruyères le Châtel The diamond anvil cell technique revolutionized high pressure physics some 25 years ago. This device takes advantage of the unusual mechanical properties of the diamond. A metallic gasket with a hole in it to confine the sample is compressed between two diamond anvils. This device allows the generation of pressures that reach 300 GPa (3 millions times atmospheric pressure), pressure at which the diamond exhibits large elastic strain [1]. The pressure reached in diamond anvil cells is very often limited by the failure of a diamond anvil. In order to prevent this phenomenon, anvils are selected on the basis of their chemical purity, and their internal strains. However, the chemical purity does not guarantee the resistance of diamond anvils under high pressure operation. In particular, when the diamonds are used in contact with H2 or Helium samples, species which diffuse in diamond. Unfortunately, helium is known to be the best pressure transmitting medium, and is often loaded for that use in diamonds anvil cells [2]. A better understanding of early breakdown of diamond anvils and an a priori diagnostic of their resistance would thus constitute a major improvement for high pressure techniques. X-ray topography helps to establish this anvils quality diagnostic, because this method evidences intrinsic crystallographic defects of the anvils. These defects are likely to influence the mechanical properties of the anvil [3]. However, the liability of x-ray topography diagnostic had to be proven. -
Ecological Comparison of Synthetic Versus Mined Diamonds
Ecological Comparison of Synthetic versus Mined Diamonds Saleem H. Ali Working Paper, Institute for Environmental Diplomacy and Security University of Vermont, January, 2011 http://www.uvm.edu/ieds Abstract The energy usage and emissions in mined versus lab-created diamonds was evaluated, based on industrial data, since these two factors are often a general indicator of environmental impact that can be useful in product comparisons. Depending on the process and the location of the mine, the data can be highly divergent and cannot be used as a singular measure of environmental impact. There is a need to develop life cycle analysis techniques from industrial ecology to conduct a detailed comparison of synthetic versus mined stones. Introduction Synthetic diamonds have come of age, and the year 2010 will be remembered as a landmark year in this regard since for the first time labs of the Gemological Institute of America (GIA) in New York were able to grade a gem quality near-colorless synthetic diamond (formed by chemical vapor deposition) , greater than 1 carat. The history of synthetic diamonds at the industrial level, goes back to patents for super-abrasives at General Electric can be traced back to several decades (Hazen, 1996). However, gem quality synthetic diamonds have only risen to prominence in the last decade with the rise of a few key companies who are taking on this growing market in concert with boutique jewelry brands. As jewelers consider environmental social responsibility more seriously in marketing their gemstone products, energy usage in mined versus lab-created gems can be an important factor in determining comparative environmental impact. -
Does Abalone Nacre Form by Heteroepitaxial Nucleation Or by Growth Through Mineral Bridges?
Chem. Mater. 1997, 9, 1731-1740 1731 Does Abalone Nacre Form by Heteroepitaxial Nucleation or by Growth through Mineral Bridges? Tilman E. Scha¨ffer,*,† Cristian Ionescu-Zanetti,†,⊥ Roger Proksch,† Monika Fritz,†,‡ Deron A. Walters,† Nils Almqvist,†,| Charlotte M. Zaremba,§,⊥ Angela M. Belcher,‡,§ Bettye L. Smith,†,⊥ Galen D. Stucky,§,⊥ Daniel E. Morse,‡,⊥ and Paul K. Hansma†,⊥ Department of Physics, University of California, Santa Barbara, California 93106; Marine Biotechnology Center and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106; Department of Chemistry, University of California, Santa Barbara, California 93106; Materials Research Laboratory, University of California, Santa Barbara, California 93106; and Department of Physics, Luleå University of Technology, S-97187 Luleå, Sweden Received August 12, 1996. Revised Manuscript Received June 10, 1997X We present experimental support for a model of abalone nacre growth that is based on mineral bridges between successive aragonite tablets rather than on heteroepitaxial nucleation. Interlamellar sheets of organic polymers delineate the aragonite tablets but allow the tablets to grow mineral bridges through pores in the sheets. Atomic force microscope images of interlamellar organic sheets from flat pearls made by Haliotis rufescens (red abalone; marine gastropod mollusk) reveal a fibrous core and holes of 5-50 nm in diameter. Scanning ion conductance microscopy shows that these holes are actually pores through the interlamellar sheets. With the help of statistical analysis we can associate the pore-to-pore spacings in the interlamellar sheets with the observed offsets of successive nacre tablets. These results, supplemented by AFM, SEM, and TEM images, support and extend the model of biofabrication of gastropod nacre which is based on mineral bridges between the aragonite tablets. -
OF SYNTHETIC DIAMONDS. Introduction
PI ^ AU9817130 IONOLUMINESCENCE (IL) OF SYNTHETIC DIAMONDS. A. A. Bettiol, K. W. Nugent, D. N. Jamieson and S. Prawer School of Physics, Microanalytical Research Centre, University of Melbourne, Parkville, 3052, AUSTRALIA. Introduction The optical properties of natural and synthetic diamonds have been extensively characterized in the past by absorption and luminescence. The use of such techniques as cathodoluminescence, photoluminescence, photoluminescence excitation and electron spin and paramagnetic resonance has resulted in the identification of many impurity and defect related optical centres in diamond [1-2]. Of the impurities found in diamond, nitrogen is by far the most abundant and hence responsible for most of the optical properties [3]. The development of diamond synthesis methods has resulted in the discovery of a number of a new optically active impurities and defects which are introduced during the growth process. These include Si, O, Ni and B [1-2]. In this study we identify a number of defect and impurity related centres in two commercially produced synthetic diamond samples by using the novel technique of ionoluminescence (IL) [4]. The first sample characterized is a Norton polycrystalline diamond detector. Signal produced in any charged particle detector is degraded if recombination of the electrons and holes occurs before the charge can be swept out by the electric field in the detector. In diamonds where the radiative recombination cross-section can be quite high, signal degradation can occur depending on the optical centres present and their lifetimes. Recombination centres with lifetimes much longer than the sweep out time will potentially saturate hence only cause a degradation of signal. -
PDF Red List of Colombian Cultural Objects at Risk
RED LIST OF COLOMBIAN CULTURAL OBJECTS AT RISK BIAN T OF COLOM D LIS T RISK RE OBJECTS A CULTURAL S T E Illegal excavationL of archIaeological sites ( guaquería ) severs the connection between an object and its context, preventing properG identificEation of the Rartefact aOnd diminiUshing its cultural meaning. As a result, the scientific study of looted sites is very limited since information essential for reconstructing ways of life has been destroyed. Thefts from museums, churches, libraries and archives irreparably damage the integrity of Three thousand pre-Columbian items seized in 2004, collections, leaving gaps that distort the historical by the Administrative Department of Security, record. from a U.S. trafficker living in Colombia. © Instituto Colombiano de Antropología e Historia (ICANH) Colombia’s National Campaign against Illicit Trafficking in Cultural Property seeks to protect Colombian heritage from such criminal acts, implementing its strategies through national and international agreements. It provides both courses and on-line training dedicated to spreading knowledge about movable cultural heritage, and to enhancing its appreciation, conservation and use. It also aims to strengthen legislation, and to publish guides, posters and informative brochures. ICOM contributes to these efforts with this Red List . If you suspect that a cultural object from Colombia may be stolen, looted or illegally exported, please contact: Ministry of Culture, Ministry of Foreign Affairs, National Police, Cultural Heritage Directorate of Heritage -
De Beers Natural Versus Synthetic Diamond Verification Instruments
DE BEERSNATURAL VERSUS By Christopher M.Welbourn, Martin Cooper, and Paul M,Spear Twoinstruments have been developed at he subject of cuttable-quality synthetic diamonds De Beers DTC Research Centre, has been receiving much attention in the gem trade Maidenhead, to distinguish synthetic dia- recently. Yellow to yellow-brown synthetic diamonds grown monds from natural diamonds. The in Russia have been offered for sde at a number of recent DiainondSureTMenables the rapid exami- gem and jewelry trade shows (Shor and Weldon, 1996; nation of large numbers of polished dia- monds, both loose and set in jewehy. Reinitz, 1996; Johnson and Koivula, 1996))and a small num- Automatically and with high sensitivity, ber of synthetic diamonds have been submitted to gem grad- this instrument detects the presence of the ing laboratories for identification reports (Fryer, 1987; 415 nm optical absorption line, which is Reinitz, 1996; Moses et al., 1993a and b; Emms, 1994; found in the vast majority of natural dia- Kammerling et al., 1993, 1995; Kammerling and McClure, monds but not in synthetic diamonds. 1995). Particular concern was expressed following recent Those stones in which this line is detected announcements of the production and planned marketing of are "passed" by the instrument, and those near-colorless synthetic diamonds (Koivula et al., 1994; in which it is not detected are "referredfor "Upfront," 1995). further tests." The DiamondViewTRfpro- Synthetic diamonds of cuttable size and quality, and the duces a fluorescence image of the surface of technology to produce them, are not new. In 1971, researchers a polished diamond, from which the growth structure of the stone may be deter- at the General Electric Company published the results of mined. -
DNA Fingerprinting of Pearls, Corals and Ivory: a Brief Review of Applications in Gemmology Laurent E
FEATURE ARTICLE DNA Fingerprinting of Pearls, Corals and Ivory: A Brief Review of Applications in Gemmology Laurent E. Cartier, Michael S. Krzemnicki, Bertalan Lendvay and Joana B. Meyer ABSTRACT: This article reviews the extraction of DNA (deoxyribonucleic acid) from biogenic gem materials (pearls, corals and ivory) for determining species identification and geographic/genetic origin. We describe recent developments in the methodology adapted for gem samples that is minimally destructive, as well as the successful DNA fingerprinting of cultured pearls from various Pinctada molluscs to identify their species. The DNA analysis methods presented here can also potentially be used for fingerprinting corals and ivory. The Journal of Gemmology, 36(2), 2018, pp. 152–160 http://dx.doi.org/10.15506/JoG.2018.36.2.152 © 2018 The Gemmological Association of Great Britain iogenic gems—often called ‘organic gems’ which consists of CaCO3 as well as protein, glycosamino- (see Galopim de Carvalho, 2018, for a recent glycans and proteoglycans (Debreuil et al., 2012). They can discussion of terminology)—are some of the be coloured by carotenoids and other types of pigments. oldest-used gem materials and have been Finally, elephant ivory from African (Loxodonta spp.) Bcherished since pre-history (Hayward, 1990; Tsounis et and Asian (Elephas spp.) elephant tusks is comprised al., 2010; Charpentier et al., 2012). Rather than having a of collagen and carbonate-rich hydroxyapatite (dahllite, geological origin, these gem materials—such as pearls, Ca10[PO4]6[CO3] • H2O; Edwards et al., 2006). Ivory precious corals and ivory (e.g. Figure 1)—are products can be found in a large number of animal species, of of biomineralisation processes in which living animals which elephant ivory is the most studied due to its value, produce mineral substances (e.g. -
Vintage Pearl Necklace with Diamond Clasp, NK-3522 the Diamond
Vintage Pearl Necklace with Diamond Clasp, NK-3522 The diamond-accented clasp in this vintage pearl necklace is dainty and elegant. Strung with round Akoya saltwater peals, this vintage jewelry piece secures with a platinum and 14k white gold navette-shaped clasp. Old European cut diamonds are arranged in a flirty bowtie down the center of the clasp. Details: Platinum and 14k white gold. Old European cut diamonds; 0.51 carats. Akoya saltwater pearls. Vintage, Circa 1930s Item # nk3522 Metal platinum and 14k white gold Circa 1930s Condition Very Good Diamond cut or shape old European cut Diamond carat weight 0.39 Diamond mm measurements 4.4 x 2.76 Diamond color G Diamond clarity SI1 Diamond # of stones 1 Diamond2 cut or shape old European Diamond2 carat weight 0.12 Diamond2 mm measurements 2.5 Diamond2 color E Diamond2 clarity SI1 and I1 Diamond2 # of stones 2 Number of pearls 52 Pearl shape near round Pearl size 7.5 - 8.2 Pearl color silver white Pearl overtone rose Other pearl info Akoya saltwater pearls, bright luster, slightly blemished complexion, adequate nacre, excellent matching Necklace length 460 mm [17.94 in] Clasp details Navette shaped clasp measuring 13x7x5mm. The clasp is platinum and the tongue is 14k white gold. 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. The gemologist/appraiser's report is included on the Detail Page for each jewelry piece.