Retailers’ Reference Guide Diamonds, Gemstones, Pearls and Precious Metals Preface Welcome to the Retailers’ Reference Guide: We have created this Guide to meet a need that Diamonds, Gemstones, Pearls and Precious Metals. has been highlighted by jewellery retailers around This ground-breaking piece of work is the result the world. Namely an accessible reference guide of the exceptional efforts of a large number of that allows jewellery retailers at all levels to members in all the CIBJO Commissions. By coming benefit from the enormous knowledge contained together in this manner we are confident that this within CIBJO. guide will assist jewellery retailing globally. I truly believe that this Guide will provide an Research has shown that empowering staff with excellent resource that will support and drive the vital knowledge about the products they sales growth for all types of jewellery retailer sell leads to sustainable sales growth. Jewellery and will become crucial to making CIBJO member consumers all around the world are looking for businesses more successful. greater information about the products we sell. Wishing you all future success. At the Marketing and Education Commission we are committed to providing jewellery retailers with the tools to sell more effectively. We can develop the most inspiring jewellery products in the world but if the retailing does not live up to the product we Jonathan Kendall President will fail to compete with other luxury products. Marketing and Education Commission, CIBJO CIBJO Retailers’ Reference Guide May 2010 How to use the Retailers’ Reference Guide This Guide is designed to provide retailers with a better Retailers’ Reference Guide contributors understanding of the fundamentals of Diamonds, Gemstones, This guide is the result of a large number of In addition many thanks for their help Pearls and Precious Metals. individuals’ exceptionally hard work and the and support to: co-operation of all CIBJO’s Sector III and Precious • Donna Baker, GIA President Metal Commissions. It has two sections: • Jean-Pierre Chalain , Swiss Gemmological The CIBJO Marketing and Education Commission Institute, SSEF • Key facts guides that act as a quick reference guide. would especially like to thank: • Andrew Cody, ICA President • Martin Coeroli, President CIBJO We recommend that these are printed and laminated • Shigeru Akamatsu of Mikimoto & Co. Pearl Commission for the text and image development to provide a simple reference on the shop floor. • James Courage, Platinum Guild International of the Pearl chapter • Dona Dirlam, GIA Library and her staff • Michael Allchin of The Birmingham Assay • Full chapters, covering Diamonds, Gemstones, Pearls • Raitu Galenon, CIBJO Pearl Commission Office for all his help and support on • Héja Garcia-Guillerminet, Laboratoire and Precious Metals in greater detail, that deliver the Precious Metals chapter Français de Gemmologie • Jonathan Kendall of De Beers Group a basic reference guide for jewellery retailers. • Matt Graydon, World Gold Council as the project sponsor • Gérard Grospiron, Grospiron Jewellers • André Marais of De Beers Group • Doug Hucker, AGTA CEO for project co-ordination and production • Michael Krzemnicki, Swiss Gemmological • Roland Naftule, CIBJO President Sector III Institute, SSEF the project Gem Materials co-ordinator • Harry Levy, Levy Gems • Jon C. Phillips of BHP Billiton for all of his • Thomas Lind, Lind Granat help and support on the Diamond chapter • Richard Peplow, Peplow Jewellers • Ken Scarratt of GIA for the text and image • Emmanuel Piat, Piat & Co. development of the Pearl chapter Coloured gemstone section written by the Gemmological Institute of America, Carlsbad, California. • Neils Ruddy Hansen All rights reserved. • Robert Weldon of the GIA for the text and • Nick Sturman, Bahrain Directorate of All rights reserved. No part of this Guide may be reproduced, republished, amended, translated or changed, image development of the Gemstone chapter Precious Metals & Gemstone Testing including all images included in the Guide, without the express written permission of CIBJO or its authorised agents. Permission to republish, reproduce and/or translate of this Guide is limited to CIBJO member organisations only, • Hanco Zwann, NEL and is subject to written agreements between CIBJO and/or its agents and the CIBJO membership organisation. CIBJO Retailers’ Reference Guide May 2010 Contents Key facts: Reference guides: Diamonds Diamonds Gemstones Pearls Precious metals Gemstones 3 Introduction to diamonds 3 Alexandrite and other chrysoberyls 3 Introduction – 3 Introduction Cultured pearls 4 Properties of diamond 6 Amethyst types of pearls 4 Common Control Mark Precious metals 5 Classifying diamonds 8 Aquamarine 5 Natural pearls 5 Gold into types 10 Other beryls 8 Cultured pearls 8 Silver 6 From rough to polished 13 Citrine 9 Pearl culturing and 9 Platinum 8 The 4 Cs 15 Emerald the molluscs 10 Palladium 9 Carat 18 Feldspar group 11 Quality of the 10 Cut 22 Garnet group cultured pearl 15 Colour 26 Jade 14 Treatment of a pearl 19 Clarity 29 Kunzite or cultured pearl 23 Certification of diamonds 31 Lapis lazuli 24 Synthetics 33 Opal 25 Diamond simulants 38 Organic gems 27 Treatments 42 Peridot 44 Unusual quartzes and chalcedony 50 Ruby 53 Sapphire 56 Spinel 58 Tanzanite 60 Topaz 63 Tourmaline 66 Turquoise 69 Zircon CIBJO Retailers’ Reference Guide May 2010 Key facts Retailers’ Reference Guide KEY FACTS Key facts: Diamonds Cut Common cutting styles • Diamonds are worn by people as potent symbols of love, devotion, pride, wealth and Cut is the shape and cutting style Asscher Cushion Emerald Heart Marquise power. of a diamond. The cut, polish and proportions of a diamond will • At least 13 factors affect determine its appearance. The shape diamond value, including of a diamond is a matter of personal fluorescence, table taste, with the round brilliant cut the percentage, symmetry and most popular. Other shapes are the other crucial details. asscher, cushion, emerald, heart, pear, • The most important factors marquise, oval, princess and trilliant. when determining the quality of a diamond are known as the 4 Cs. These are the diamond’s Carat Pear Princess Oval Round Trilliant carat weight, its cut, its colour and its clarity. Carat is often mistakenly used to • The key thing to note is that refer to a diamond’s size, but it is no one C is more significant actually a measure of weight. One than another. A particular carat (equivalent to 200 milligrams) combination of the 4 Cs can can be divided into 100 “points”. be chosen to suit a particular A 0.75 carat diamond may also budget, occasion, design or be described as a 75-point or jewellery piece. ¾ carat diamond. Larger diamonds are found less Guide to approximate carat size frequently in nature, so they can command a significantly higher price. For instance, a one carat diamond will cost more than two ½ carat diamonds of equal colour, clarity and cut. 2 CTS 1.5 CTS 1.25 CTS 1 CTS 0.75 CTS 0.50 CTS 0.25 CTS 0.10 CTS 75 points 50 points 25 points 10 points All rights reserved. No part of this Guide may be reproduced, republished, amended, translated or changed, including all images included in the Guide, without the express written permission of CIBJO or its authorised agents. Permission to republish, reproduce and/or translate of this Guide is limited CIBJO Retailers’ Reference Guide May 2010 to CIBJO member organisations only, and is subject to written agreements between CIBJO and/or its agents and the CIBJO membership organisation. Colour Clarity KEY FACTS Diamonds are found in almost every colour expert under controlled lighting conditions Every diamond is unique. Nature ensures The number, type, colour, size and position of the rainbow, but white-coloured diamonds and compared against a master set for that each diamond is as individual as the of these inclusions can affect the value of a remain the most popular. There are more accuracy. Those at the upper end of the person who wears it. Naturally-occurring diamond. However, many can only be seen by than 20 subtle grades of colour, identified in scale will be more expensive, as they are features – known as inclusions – provide a experts using a 10-power magnification loupe. alphabetical order from D-Z. Variations are so rarer. However, they are difficult to discern special fingerprint within the stone. Usually Even with the loupe, the tiniest inclusions can slight that colours must be graded by an with the naked eye. invisible to the naked eye, these tiny marks be very difficult to find. are minerals or fractures which appeared while Flawless diamonds are rarer and thus, more the diamonds were forming in the earth. expensive, but small inclusions do not affect Colour Grading scales* the beauty or the brilliance of a diamond. GIA CIBJO / IDC Scan. D.N. AGS GIA D Exceptional White+ 0 D River E Exceptional White 1 E Colourless F Rare White+ Top 2 F Wesselton G Rare White 3 G H White Wesselton 4 H Clarity Grading scales* Near I Top Crystal I GIA CIBJO / IDC Scan. D.N. AGS Key: colourless Slightly Tinted White 5 J Crystal J LC Loupe clean FL FL 0 K 6 K Tinted White Top Cape LC F Flawless L L Faint Faint IF Internally flawless IF IF yellow 7 M M 1 VVS Very, very slightly VVS1 VVS1 VVS1 N N included (very, very O 8 O small inclusions) VVS2 VVS2 VVS2 2 P P VS Very slightly included yellow VS VS VS 3 light Very Q Q 1 1 1 (very small inclusions) R R SI Slightly included VS VS VS 4 9 2 2 2 S Tinted colour Cape S (small inclusions) SI SI SI 5I Included T T 1 1 1 P Piqué U U SI2 SI2 SI2 6 V V I P P 7,8 W W 1 1 1 10 Light yellow X X I2 P2 P2 8,9 Y Y I P P 9,10 * There are other grading systems used Z Z 3 3 3 by laboratories around the world.