synthetic corundum
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                                                    A Sapphire's Secret — Synthetic Yellow Sapphire- Date: 2017-07-01
   At the Lotus Gemology laboratory in Bangkok, we often get parcels of relatively uniform stones. But sometimes it is in this routine testing that we uncover surprises. 
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                                                    Book | Ruby & Sapphire | A Collector's Guide | 2014 | Order Page Introducing…Ruby & Sapphire: A Collector's Guideby Richard W. Hughes
 with photographs by Wimon Manorotkul and E. Billie HughesThis impressive coffee-table style volume takes readers into the secret world of ruby and sapphire, through the pen and lens of international expert, Richard Hughes. The author guides readers with the steady eye of a connoisseur, explaining what collectors should look for in ruby and sapphire. Many pictured pieces feature actual auction prices, aiding collectors in their buying decisions. Illustrated with more than 400 magnificent color photographs, for anyone with an interest in precious stones, this is a visual and intellectual feast of the most delicious order. Published 2014; Sold Out Hardcover with Dust Jacket 
 384 pages; 240 × 280 mm (9.45 × 11 inches); 2.4 kg shipping weight
 Full Color Throughout
 Content1. RésuméHistory2. SourceGeologyValley of SerpentsAfghanistanAustraliaIndiaKenyaLaosMadagascarMalawiMozambiqueMyanmarNepalPakistanRwandaSri LankaTajikistanTanzaniaThailand & CambodiaThailand & CambodiaUSA–MontanaVietnam3. ConnoisseurCuttingFrom Pigeon's Blood to Peacock's NeckRuby & Sapphire PricesDoes Size Matter?The Tao of Jewelry4. ForensicInner SpaceEnhancementsConnoisseurship of Crystals5. HeartGem Cutting in ThailandThe Thai Jeweler's Art6. LibraryLibraryLibrary7. PortfolioPortfolioIndex
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                                                    Book | Ruby & Sapphire | A Gemologist's Guide | Order PageIntroducing…Ruby & Sapphire: A Gemologist's Guideby Richard W. Hughes 
 with Wimon Manorotkul and E. Billie HughesThis massive volume is the most comprehensive book ever written on a single precious stone. Designed as a companion volume to Ruby & Sapphire: A Collector's Guide, it is aimed specifically at working gemologists, appraisers and students. Based on Richard W. Hughes' 1997 classic, Ruby & Sapphire, this edition is fully updated. The product of nearly 40 years of firsthand experience and research, it covers every aspect of the subject from A–Z. History, sources, prices, quality analysis, synthetics and treatments, everything is here. Ruby & Sapphire—A Gemologist’s Guide represents the definitive reference on the subject. With over 1000 photos, maps and illustrations and 3500 references, it is nothing less than a tour-de-force of gemological scholarship. Published 2017; Sold Out 
 •International Shipping & Handling from Thailand 
 Ships via International Parcel Air (2-3 weeks)Hardcover with Dust Jacket 
 816 pages; 240 x 280 mm (9.45 x 11 inches); 4.6 kg shipping weight
 Full Color Throughout
 GalleryTitle PageContentsContentsIntroduction1. History2. Chemistry & Crystallography3. Properties & Phenomena4. Color & Luminescence5. Inclusions6. Treatments7. Synthetic Corundum8. Assembled Stones9. Methods of Fashioning10. Judging Quality11. Geology12. World SourcesAfghanistanAustraliaChinaColombiaFrance & GreenlandIndiaKenyaLaosMadagascarMalawiMozambiqueMyanmarNepal & NigeriaPakistanRwandaSri LankaTajikistanTanzaniaThailand/CambodiaUSAVietnamAppendix A: Tagore's Mani-MalaAppendix B: Prices & ID Flow ChartsIndexClick on the icon to download a corrected Table of Contents and Errata sheet for the current volume (PDF). Comments from reviewers…Voilà un livre de poids, 735 pages et plus de 4 kg qui enrichira vos connaissances historiques comme scientifiques et gemmologiques. L' auteur, bien connu des gemmologues, nous offre un nouveau voyage dans l' univers des corindons. C' est un livre à regarder, approcher, toucher, feuilleter, découvrir enen l' ouvrant avec à la fois impatience et retenue, pour finalement s' y abandonner. C' est une leçon de vie, un livre-compagnon à déguster sans modération. —Association Française de Gemmologie 
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                                                    Buying at the Source — Dick's Law and Other Sundry Maxims of the East- Date: 2010-05-01
   An essay on buying gems at the source in Asia, with a discussion of how con men play on the greed of those who believe gems will be cheaper at the mines. 
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                                                    Con-juring Ruby — A Heated Flux Synthetic- Date: 2025-07-01
   Distracting features in this ruby could easily cause gemologists to misidentify the stone. Learn more about how we unmasked this tricky synthetic. 
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                                                    Curved Banding in Flame-Fusion Synthetic Sapphires- Date: 2019-06-01
   Short-wave fluorescent illumination provides a useful tool to spot curved banding in flame-fusion synthetic sapphire. 
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                                                    Hidden Treasure — Collecting Books on Ruby & Sapphire- Date: 2020-08-01
   A discussion of the literature of ruby and sapphire (corundum), with particular emphasis on the most collectible books covering ruby and sapphire around the world. 
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                                                    Padparadscha or Pretender — An Unusual Pink-Orange Sapphire- Date: 2016-06-01
   An orangish pink “padparadscha” sapphire was submitted for testing at Lotus Gemology’s Bangkok laboratory. Testing showed a number of conflicting features that suggested the gem was a cleverly treated synthetic pink sapphire designed to imitate natural padparadscha. 
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                                                    Pleochroism in Faceted Gems — An Introduction- Date: 2014-10-25
   The phenomenon of pleochroism in doubly refractive (DR) gemstones is described, as it relates to overall color appearance in the context of faceted gems. With strongly pleochroic gems, pleochroism can be seen in faceted gems, even if the table facet is oriented perpendicular to an optic axis. This is because facets change the direction of light as it moves through the gem. 
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                                                    Verneuil Synthetic Corundum ID — Dangerous Curves- Date: 2005-10-01
   Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features. 















































































































