DOCSLIB.ORG

Colored Gemstones Cultured Pearls

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
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. Areas: In the following pages you’ll explore these themes and PRODUCT KNOWLEDGE • Pearls find information to help customers understand their signifi- • Disclosure natural • History of Jewelry cance. The lesson begins with the romance of pearls. • Designer & Brand Name Jewelry Next, you’ll see how pearls are cultured. You’ll learn about • Custom-manufactured Items factors that affect beauty, quality, and value. You’ll also find SERVICES AND GUARANTEES out how these apply to different types of pearls. Finally, • Store Service Programs you’ll examine ways to guide your customers into the fasci- CUSTOMER SERVICE • Building Customer Relations nating world of pearls. SELLING PROCESS • Customer Needs • Building the Sale •Closing the Sale OPERATIONS • Merchandise Maintenance BUSINESS ETHICS • FTC Guidelines •Trade Practices Lesson Objectives When you have successfully completed Photo courtesy Cathleen Bunt. this lesson, you will be able to: • Describe how cultured pearls are created. • Explain factors that affect pearl beauty, quality, and value. • Discuss the features and benefits of different types of pearls. • Open customers to the possibilities of pearl wardrobing. 2 Colored Gemstones 5 Cultured Pearls PEARL TRADITIONS Since the dawn of history, pearls have been counted among the most beautiful, magical, and valuable of gems. Early hunter -gath- erers probably found pearls during their search for food, making pearls among the first gems treasured by humans. Pearls have also appeared in the folktales, religions, and popular traditions of many cultures. Here are a few examples you might share with customers: • For centuries, many people in Asia believed that pearls began with drops of divine moisture falling from dragons in the sky. When the drops landed in seashells and were Throughout history pearls have been nourished by moonbeams, they grew into pearls. one of the most highly prized and sought after gems. • Pearls have long been seen as religious symbols. In Photo courtesy Japan Pearl Exporters Association. Buddhist art, pearls represent enlightenment. A Christian parable compares the kingdom of heaven to a pearl of great price. According to Islamic tradition, every event – past, present, and future – is recorded on a vast pearl that extends from heaven to earth. • In the ancient Roman world, pearls were the most concentrated form of wealth. Egypt’s queen Cleopatra once bet the Roman general Marc Antony that she could consume the value of a whole nation in one meal. To win the wager she crushed a large pearl, mixed it in glass of wine, and drank it. Because of their appearance and aquatic origins, pearls were associated with the bewitching beauty of the full moon and the life-giving power of water. From these natural links, pearls grew to symbolize purity and love. Ultimately, the rich traditions surrounding pearls made them birthstones for the month of June, as well as designated gems for both the 3rd and 30th wedding anniversaries. (You’ll learn more about birthstones and anniversary gems in Lesson 12.) Cleopatra Today, pearls still embody the meanings they’ve possessed for thou- sands of years. The science and magic of culturing have added new dimen- sions, too. Though you probably have only cultured pearls in your show- cases, let’s look at the original inspirations. Colored Gemstones 5 3 Cultured Pearls NATURAL PEARLS Natural pearls are produced by about two dozen kinds of mollusks, including oysters, mussels, and other shellfish. (Pearl oysters, however , are more closely related to scallops than to common edible oysters). The process of natural pearl formation usually begins when an irritant of some kind accidentally enters the mollusk’s shell. Many people think a grain of sand is responsible, but the “trigger” is more often a tiny worm, crab, or fish. As a defensive response, the mollusk coats the invader with layer after layer of nacre (NAY-ker). This is composed mostly of microscopic calcium carbonate crystals which accumulate like overlapping shingles. Nacre is Natural pearls are similar to the inner lining of the mollusk’s shell, more commonly known as produced by several mother-of-pearl. Besides protecting the mollusk, nacre is responsible for dozen kinds of mollusks. pearl’s distinctive beauty. Natural pearls were once found in significant quantities around the world. They came from saltwater bodies such as seas and oceans, and also from the freshwaters of streams, rivers, and lakes. The most famous source of natural saltwater pearls was the Persian Gulf. This locale was fished commercially before 300 BC. The pearls found there were called “Oriental” pearls and have often been mentioned in literature and history. Much later, Columbus and the explorers who followed him discovered salt- Throughout history, the best known water pearls in the New World. In the 1800s, new kinds of natural source of natural salt-water pearls was the Persian Gulf. saltwater pearls were recovered as by-products of fishing for mother-of-pearl shell in Australia and French Polynesia. Natural freshwater pearls were available treasures, too. The emperors of China decked them- selves in pearls from the rivers of their kingdom. Freshwater pearls were also found in much of Europe and America. Old European laws decreed them to be royal property . Native tribes prized those from the waters of the country that became the United States. Over the centuries, natural saltwater pearls gradually disappeared. Chinese sources became depleted almost 2,000 years ago. Most American saltwater pearls were gone by the 1600s, and their freshwater kin followed in the 1800s. After more than 20 centuries, the flow of pearls from the Persian Gulf dropped to a trickle in the early 1900s. In most cases the cause was overfishing, but in modern times, pollution became a factor as well. 4 Colored Gemstones 5 Cultured Pearls Natural pearls are still found in limited numbers at a few locations. You’re most likely Cultured Pearls to see them in antique stores and estate auctions. (You may not recognize them because it takes X-ray testing to tell the difference between natural and cultured pearls.) For the most part, Natural It takes x-ray to tell the Pearls difference between natural natural pearl’s ancient place in the gem kingdom and cultured pearls. has been taken over by the cultured pearl. CONCH AND MELO PEARLS he Queen conch (kahnk) is a large snail-like mollusk that Tinhabits parts of the western Atlantic Ocean and the Caribbean Sea, from Bermuda to South America. Famous for its ornate shell, this animal also produces the gems known as conch pearls. The finest conch pearls are delicate rose to deep orangish “salmon” pink. They have a porcelain look, with a silky sheen and a surface patterning that’s described as “flame structure”. Similar pearls come from other sea snails called Melo, which Conch Pearl. live in coastal waters of Southeast Asia. These are golden Photo courtesy Tino Hammid. yellow to amber orange in color, with similar sheen and patterning. Both types occur in other colors as well. Conch and Melo pearls are made of calcium carbonate. They form inside a mollusk, and are as rare as natural pearls. Many dealers and gemologists, however, say they aren’t true pearls because they don’t have a nacre coating with the shingle-like structure. In schol- arly publications they’re often called “calcareous concre- tions” or “non-nacreous pearls”. They can be very beau- tiful, though – and amazingly expensive. At a 1999 jewelry auction in Hong Kong, a single Melo pearl sold for almost $500,000. Now, THAT’S appreciation of nature’s rarity! Queen conch shell Colored Gemstones 5 5 Cultured Pearls CULTURED PEARLS Natural pearls form without human help of any kind. Creating a cultured pearl, on the other hand, involves human intervention and care. It’ s important to make this difference clear to customers. You might say cultured pearls depend on the same life processes, but people play a role in their formation and growth.
Load more

Recommended publications
  • 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.
    [Show full text]
  • Branding for Sabah Pearl 2018
    BRANDING FOR SABAH PEARL Tan Yin Yin Bachelor of Applied Arts with Honours (Design Technology) 2018 BRANDII\'G FOR SABAH PEARL 'IlL'1 YII\' YIN Th,s project is submitted in partial fulfillment of the requirements for the degree of Bachelor of Arts with Honors (IlE'sign Technology) Faculty of Apphed and Creative Arts UWVERSITI NiALl, YSIA SARAWAK 2013 PENJENAMAAN UNTUK MUTIARA SABAH TAN \1N \1N Pr'Diekilll merupakan salah satu keperluan untuk ljazah Sarjana Seni Gunaan dengan (Teknologi Sem Reka) Fakulti Seni. Gunaan dan Kreatif UNlVERSITI Mll.Lll. YSIA SARA WAK 2018 ii PIE'.u~ (leI> ( 'd FUll.! \'t","\r ?r -:~ <:' 1 R~pc.n :J :·::: ~r s PhD O(C'L\.R:HIO:--: Of ORIGI);_\L \,"ORb. dar ot ._ ;':II I S .Studt-nt's Decl"l'.1(1oD r . ICI"YtYl)!h (J 1f O. ~7.)~m fa(,tlt'r° fAr p.ii~4~f). (((r.e~ ~y'e, Arts IPLZ-l..t: =: e\"Dl8::..r ::: ~~ l·D ~:\T~~,.'\.:J:::. :-"L';'IRJC:--:O :1...'\-n f..I,.C"""L n"! htrebr dtcl:m' ~hat the wcrt tr~m i l'd .. [a.(!d.t' .J..r ~ r. ,;. o::Mh:. ... P..e.~ .d ...... _......... _..... ................... !"i Ill)" " n~l!Ji\ l we.rk I han: c o, Or:'le- j n- ot::. ilDr othH S'tud .. n;:~ wort vr trow any other sourcE' __ t :': c~ p: \\h~lt dut refH t'o{'e or lC' t.no":lt'd~tI1l ..nt!i ~l dt t::pJ.i.C1tl~ · t.n [he te:;:l on ha~ anr part been ';\,III('n for Ill t by " o.
    [Show full text]
  • 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.
    [Show full text]
  • An Environmental History of Nacre and Pearls: Fisheries, Cultivation and Commerce." Global Environment 3 (2009): 48–71
    Full citation: Cariño, Micheline, and Mario Monteforte. "An Environmental History of Nacre and Pearls: Fisheries, Cultivation and Commerce." Global Environment 3 (2009): 48–71. http://www.environmentandsociety.org/node/4612. First published: http://www.globalenvironment.it. Rights: All rights reserved. Made available on the Environment & Society Portal for nonprofit educational purposes only, courtesy of Gabriella Corona, Consiglio Nazionale delle Ricerche / National Research Council of Italy (CNR), and XL edizioni s.a.s. An Environmental History of Nacre and Pearls: Fisheries, Cultivation and Commerce Micheline Cariño and Mario Monteforte he world history of nacre and pearl i sheries, cultivation, and trade is a vast topic. From an- tiquity to the present, it takes us on a journey from myths about the origins of the pearls and their dif erent traditional uses, to complex in- teractions between societies, economies, cul- tures, and environmental issues. Such a history T needs the support of dif erent disciplinary ap- proaches. Biological and ecological studies tell us how oysters develop and form a pearl. Socioeconomic studies of pearls i sheries show several historical constants, such as excessive i shing, a specii c organization of labor, and an unequal distribution of benei ts. Studies on the trade of nacre and pearls highlight the cultural characteristics of dif erent markets in the world. History of science emphasizes the link between the depletion of this natural resource and the scientii c investigations that led to the development of pearl oyster and pearl culture technologies. Nevertheless, the most interesting way to look at the exploitation of pearls is from the perspective of environmental history, to high- light their important role in humanity’s evolving relationship with natural resources.
    [Show full text]
  • 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.
    [Show full text]
  • Histopathology of Oedema in Pearl Oysters Pinctada Maxima
    Vol. 91: 67–73, 2010 DISEASES OF AQUATIC ORGANISMS Published July 26 doi: 10.3354/dao02229 Dis Aquat Org Histopathology of oedema in pearl oysters Pinctada maxima J. B. Jones*, M. Crockford, J. Creeper, F. Stephens Department of Fisheries, PO Box 20, North Beach, Western Australia 6920, Australia ABSTRACT: In October 2006, severe mortalities (80 to 100%) were reported in pearl oyster Pinctada maxima production farms from Exmouth Gulf, Western Australia. Only P. maxima were affected; other bivalves including black pearl oysters P. margaratifera remained healthy. Initial investigations indicated that the mortality was due to an infectious process, although no disease agent has yet been identified. Gross appearance of affected oysters showed mild oedema, retraction of the mantle, weak- ness and death. Histology revealed no inflammatory response, but we did observe a subtle lesion involving tissue oedema and oedematous separation of epithelial tissues from underlying stroma. Oedema or a watery appearance is commonly reported in published descriptions of diseased mol- luscs, yet in many cases the terminology has been poorly characterised. The potential causes of oedema are reviewed; however, the question remains as to what might be the cause of oedema in molluscs that are normally iso-osmotic with seawater and have no power of anisosmotic extracellular osmotic regulation. KEY WORDS: Oedema · Pinctada maxima · Osmosis · Lesion · Mortality Resale or republication not permitted without written consent of the publisher INTRODUCTION the threat of disease and a complex series of transport protocols and separation of pearl farm lease areas The annual value of production of the pearling has been required (Jones 2008).
    [Show full text]
  • DIAMOND Natural Colorless Type Iab Diamond with Silicon-Vacancy
    Editors Thomas M. Moses | Shane F. McClure DIAMOND logical and spectroscopic features con- Natural Colorless Type IaB firmed the diamond’s natural origin, – Diamond with Silicon-Vacancy despite the occurrence of [Si-V] emis- Defect Center sions. No treatment was detected. Examination of this stone indicated The silicon-vacancy defect, or [Si-V]–, that the [Si-V]– defect can occur, albeit is one of the most important features rarely, in multiple types of natural dia- in identifying CVD synthetic dia- monds. Therefore, all properties should monds. It can be effectively detected be carefully examined in reaching a using laser photoluminescence tech- conclusion when [Si-V]– is present. nology to reveal sharp doublet emis- sions at 736.6 and 736.9 nm. This Carmen “Wai Kar” Lo defect is extremely rare in natural dia- monds (C.M. Breeding and W. Wang, “Occurrence of the Si-V defect center Figure 1. Emissions from the Screening of Small Yellow Melee for in natural colorless gem diamonds,” silicon-vacancy defect at 736.6 and Treatment and Synthetics Diamond and Related Materials, Vol. 736.9 nm were detected in this Diamond treatment and synthesis 17, No. 7–10, pp. 1335–1344) and has 0.40 ct type IaB natural diamond. have undergone significant develop- been detected in very few natural type ments in the last decade. During this IIa and IaAB diamonds over the past showed blue fluorescence with natural time, the trade has grown increasingly several years. diamond growth patterns. These gemo- concerned about the mixing of treated Recently, a 0.40 ct round brilliant diamond with D color and VS2 clarity (figure 1) was submitted to the Hong Figure 2.
    [Show full text]
  • Early Ontogeny of Jurassic Bakevelliids and Their Bearing on Bivalve Evolution
    Early ontogeny of Jurassic bakevelliids and their bearing on bivalve evolution NIKOLAUS MALCHUS Malchus, N. 2004. Early ontogeny of Jurassic bakevelliids and their bearing on bivalve evolution. Acta Palaeontologica Polonica 49 (1): 85–110. Larval and earliest postlarval shells of Jurassic Bakevelliidae are described for the first time and some complementary data are given concerning larval shells of oysters and pinnids. Two new larval shell characters, a posterodorsal outlet and shell septum are described. The outlet is homologous to the posterodorsal notch of oysters and posterodorsal ridge of arcoids. It probably reflects the presence of the soft anatomical character post−anal tuft, which, among Pteriomorphia, was only known from oysters. A shell septum was so far only known from Cassianellidae, Lithiotidae, and the bakevelliid Kobayashites. A review of early ontogenetic shell characters strongly suggests a basal dichotomy within the Pterio− morphia separating taxa with opisthogyrate larval shells, such as most (or all?) Praecardioida, Pinnoida, Pterioida (Bakevelliidae, Cassianellidae, all living Pterioidea), and Ostreoida from all other groups. The Pinnidae appear to be closely related to the Pterioida, and the Bakevelliidae belong to the stem line of the Cassianellidae, Lithiotidae, Pterioidea, and Ostreoidea. The latter two superfamilies comprise a well constrained clade. These interpretations are con− sistent with recent phylogenetic hypotheses based on palaeontological and genetic (18S and 28S mtDNA) data. A more detailed phylogeny is hampered by the fact that many larval shell characters are rather ancient plesiomorphies. Key words: Bivalvia, Pteriomorphia, Bakevelliidae, larval shell, ontogeny, phylogeny. Nikolaus Malchus [[email protected]], Departamento de Geologia/Unitat Paleontologia, Universitat Autòno− ma Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain.
    [Show full text]
  • 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
    [Show full text]
  • Gem Crystal Surface Features Spherical Cultured Pearls Aquamarine
    Gems&Jeweller y Spring 2012 / Volume 21 / No. 1 Gem crystal Spherical Aquamarine- surface features cultured pearls coloured glass The Gemmological Association of Great Britain MARCUS MCCALLUM FGA PRECIOUS STONES, BEADS & PEARLS A wide range of precious and semi-precious stones, beads and freshwater pearls, personally selected from around the world. Unusual stones a speciality. ROOM 27-31, NEW HOUSE 67-68 HATTON GARDEN, LONDON EC1N 8JY TELEPHONE: +44(0)20 7405 2169 FACSIMILE: +44(0)20 7405 9385 email:[email protected] www.marcusmccallum.com Gems&Jewellery / Spring 2012 / Volume 21 / No. 1 Gem-A CalendarEditorial Gems&Jewellery Winds of change This year is turning in to a busy one for Gem-A. As reported in Gem-A News and Views (page Spring 40), we have a lease renewal on our Greville Street premises which will lead to a thorough refurbishment — something which those of you who know the building will agree is much needed. This will provide an excellent opportunity to reinvigorate both our onsite teaching facilities and the services we can offer members. How can we afford this you may ask, when only a very few years 12 ago the Association was in poor health financially? The fact is that over the last few years we have run a very tight ship knowing we had these costs looming. We have focused on what we are good Contents at and the things which are the core aspects of our business. This has led to the ceasing of loss- making operations, such as the laboratory, and an increase in students and thus revenue from our education, though it must be qualified that this increase is from overseas rather than the UK.
    [Show full text]
  • 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.
    [Show full text]
  • Ž Culture Potential of the Pearl Oyster Pinctada / Imbricata from The
    Aquaculture 189Ž. 2000 375±388 www.elsevier.nlrlocateraqua-online Culture potential of the pearl oyster žPinctada imbricata/ from the Caribbean. II. Spat collection, and growth and mortality in culture systems H.-JorgÈ Urban) Facultad de Ciencias, Departamento de Biologõa, Seccion de Biologõa  Marina, UniÕersidad del Valle, A.A. 25360, Cali, Colombia Received 26 August 1999; received in revised form 23 February 2000; accepted 4 April 2000 Abstract Temporal variation in abundance of larvae and spat of the pearl oyster Pinctada imbricata was studied at several locations on the Colombian coast from May 1997 to June 1998. Larvae were sampled with bongo nets and spat were harvested from collectors at monthly intervals. Abun- dances of predators Ž.Cymatium gastropods, and portunid, xanthid and majiid crabs were also recorded. A relationship between salinity, particulate organic matter and larvae abundance was observed, leading to peaks in abundance of spat on collectors some weeks later. Average catch rates of 10 spat collectory1 monthy1, using collectors made of cheap easily accessible materials, indicate that availability of P. imbricata is sufficient to initiate and support aquaculture of this species. Growth and mortality rates of juveniles in three different culture systems at two densities Ž.20% and 30%, i.e. percentage of available area covered by juveniles showed that density within the same culture system had no effect on growth, but that growth differed significantly among the three culture systems. Growth in ``bag'' systems was lower than in boxes whereas growth in ``suspended'' and ``bottom'' boxes was similar and comparable to the growth of a natural population.
    [Show full text]