Publish Year: 1986 Title: Summer 1986 Gem News International Abstract: Colored Stones at Tucson 1986
            Cat’s-eye Kunzite: From South Dakota Deposit
            Covellite: Several Firms Selling
            Lepidolite: Cabochons up to 20 ct.
            Magnesite: Dyed Blue to Imitate Turquoise
            Pectolite: From Santo Domingo
            “Rainbow” Moonstone: Cabochons from India
            Spurrite: Numerous Specimens of Rough
            Taaffeite: Two Unusual Crystals
Other Colored Stones
            Twinned Star Spinel
            Wagon-Wheel Quartz
Announcements
            Sams Collection on Display in Houston
            GIA GemFest Scheduled
            New Categories, Winners, in Scheutz Design Contest
            Joint Committee Formed
            India Gems & Jewellery Fair
            INTERGEM ‘86
            Hong Kong Jewellery and Watch Fair

To view the full section, download the PDF above. @topic:2


Publish Year: 1991 Title: Summer 1991 Gem News International Abstract: Diamonds
            DeBeers Unveils Centenary Diamond
            Large "Chameleon" Diamond
            Soviet Production Estimates Updated
            Australian Marine Search for Stones
            World-Record Auction Price for a Diamond
            Update on Diamond Mining in Brazil
            Jewelry-Quality Diamond Crystals
            Bluish Gray Synthetic Diamond thin Films Grown on Faceted Diamonds
Colored Stones
            African Gem Update
            Amethyst from Afghanistan
            Unusual Corundum/Mica Carving Material
            Joint Venture for Russian Emeralds
            Large Carved Labradorite
            Fine Greenish Blue Opal
            Another Phenomenal Organic Gem Material
            Cultured Pearls Auction
            Green Zoisite
Enhancements
            Faceted Aqua Aura Update
            Plastic-Treated Jadeite
            Dyed Quartzite Imitation of Dyed Jadeite
Synthetics and Simulants
            Chatham Signs Agreement with Japanese Crystal Grower
            Chatham Issues Warning on Trademark Infringements
            Novel Fiber-Optic Glass
            New Glass Imitation of Lapis Lazuli
            "Encapsulated" Mexican Opal
            Plastic Imitation Opal from Thailand
            Update on Soviet Synthetics
Instrumentation
            Loupe with True Darkfield Illumination
            New Cutting Machines Developed
Announcements
            Canadian Gemmological Assn. to hold Conference in October

To view the full section, download the PDF above. @topic:8


Publish Year: 1986 Title: Spring 1986 Gem News International Abstract: Diamonds
            India: New Deposits Discovered
            Japan: World’s Largest Synthetic Industrial Diamond
            South Africa: Diamond Inclusions in Pyrope
            Sri Lanka: Geological Exploration Planned
Colored Stones
            Fade Testing Yellow Sapphire
            Pala in Sri Lanka
            Unusual Sri Lankan Sapphires
Synthetics
            “Watermelon” Beryl
Announcements
            Lizzadro Museum of Lapidary Art
            World Diamond Conference in Tel Aviv

To view the full section, download the PDF above. @topic:2


Publish Year: 1985 Title: Fall 1985 Gem News International Abstract: Diamonds
            Australia: Exploratory Drilling in Northern Territory
            Botswana: Production Increased from 1983 to 1984
            Ghana: Government Expands Diamond-Mining Concessions
            Namibia: Two Companies Doing Underwater Diamond Mining
            Sierra Leone: Three Large Diamonds (100 ct each) Found
            U.S.: Exploration Continues Among Kimberlite Deposits in Michigan
Colored Stones
            Amethyst: Clean Faceting Grade Coming from New Find in Brazil
            Aquamarine: Steady Supply Imported into Idar-Oberstein from Nigeria
            I.C.A. Congress: First Meeting Held in Idar-Oberstein May 20-22
            Pearls: 1984 Japan Harvest Was a Disappointment
            Phantom Quartzes: Spectacular Crystals Produced in Minas Gerais Region
            Sapphire: Unique “Star of David” Uncut Yogo Specimen
Announcements
            Fabergé Imperial Egg Auctioned by Sotheby’s New York on June 11
            1986 Tucson Gem & Mineral Show Dates Confirmed as February 13-16
            Munich’s INHORGENTA 86 Will Take Place February 7-11

To view the full section, download the PDF above. @topic:8


Publish Year: 1985 Title: Summer 1985 Gem News International Abstract: Diamonds
            Africa: Exciting New Diamond Find in Guinea; Kimberley Diamonds Dated
            Australia: Production at Argyle Mines Declines
            Canada: Exploration Scheduled in British Columbia
            China: “Exceptionally Beautiful” Diamonds Discovered
            U.S.: Anomalous Diamond Found in Alaska
Precious Metals
            Alluvial Gold Located by Geological Survey of India
            Bacterial Gold Mining Proposed in British Columbia
            Development of Bolivian Placer Gold Deposits Planned
            Gold and Silver Exploration in Guatemala
            Saudi Arabian Gold Mining
Synthetics and Simulants
            Method for Coating with Synthetic Diamond
            New Man-Made Materials Developed
            Plastic Scrimshaw
Announcements
            Hong Kong Jewelry & Watch Fair Scheduled for September 10-13, 1985
            European Conference on Precious Stones Scheduled for October 18-21 in Antwerp
            Munich’s INHORGENTA 86 Fixed for February 7-11, 1986
            Judy Evans of Minneapolis Wins 1985 Schuetz Jewelry Design Contest
            L.A. County Museum of Natural History unveils “Gemstones and Their Origins”

To view the full section, download the PDF above. @topic:2


Publish Year: 1985 Title: Spring 1985 Gem News International Abstract: Diamonds
            Australia: Potentially Major New Diamond Discovery in Northern Territory
            Canada: Geological Survey of Ontario Encourages Diamond Exploration
            Israel: Production, Exportation and Sales Increasing on a Wave of Recovery
            Sierra Leone: Government Purchases BP’s Share, Controls Mining Industry
Colored Stones
            Australia Produces 500+ Carat Opal from a New Locality
            Sri Lanka Looks at Mechanized Gem Mining
            Possibly World’s Largest Diaspore from Deposit in Turkey
Precious Metals
            Colombia Announces an Important Gold Deposit near Brazilian Border
            Scotian Mineral Exploration to Spend $3 Million Searching for Gold in Nova Scotia
            Gold Has Been Discovered in Finland
            Gold Production Will Begin in Southern Mali This Year
            CSIRO Division in Australia Has Developed an Improved Gold-Sampling Technique
            China Offers Loans to Individual Gold Miners to Encourage Exploration and Mining
Synthetics
            Further News on the Growth of Synthetic Gem Diamonds
            More on Russian Hydrothermal Synthetic Emeralds
Tucson 1985
            Beryl: Abundance of Aquamarines from New Source in Nigeria
            Diamond: Many Dealers Had Booths, Did Very Well
            Garnet: Various Types Being Mined in Mexico, New Mexico, Colombia, Africa
            Opal: Three Unusual Types Presented
            Parisite: A Dozen Large Crystals from Colombia Offered for Sale
            Tourmaline: Relatively New Yellow Tourmaline from Zambia Prominent
            Synthetics: Many Synthetic Materials, Particularly Amethyst, Available for Sale
Announcements
            ISA to Host First North American Meeting of F.G.A.s and G.G.s in Atlanta
            New Gemological Journal from Sri Lanka
            World Congress of Jewelry Appraisers to Convene in NYC in 1986
            Hong Kong Jewelry and Watch Fair Scheduled for September
            Permanent Exhibit “Gemesis: Gemstones and Their Origins" opens in L.A.
            ICA to Sponsor Colored Gemstone Congress in Idar-Oberstein May 20-22

To view the full section, download the PDF above. @topic:8


Publish Year: 1984 Title: Winter 1984 Gem News International Abstract: Diamonds
            Australia: Mining Magazine Reports Loan for Argyle Development
            India: Nearly 50 ct Golconda “D” Diamond Reappears
            Thailand: Noted Gemologist Sinkankas Reports on Alluvial Diamonds
            USA: Diamond Melts in Laboratory Accident at Cornell University
                     Punch-Jones Diamond Sold at Sotheby’s
                     World’s Largest Uncut Diamond (890 ct) On Display at Smithsonian
            USSR: Scientists at USSR Academy of Science Produce Synthetic Diamond
Colored Stones
            Yellow-Green Chrysoberyl Found in Queensland, Australia
            Sri Lanka Cancer Institute Uses X-ray Equipment to Irradiate Yellow Sapphires
            One of Largest, Finest Gem-Quality Opals Ever Discovered Found in Mexico
            Notes on Danburite, Zircon, and Andalusite Translated from Spanish Gemology Bulletin
            Treated Moroccan Anglesites
            Large, Very Fine Emerald Crystal Recently Discovered in North Carolina
Precious Metals
            Significant Gold and Ore Deposits Found in Alaska
            First Precious Metals Refinery in Asia outside Japan Opens in Singapore
            Sri Lankan Gold Jewelry to be Hallmarked
Synthetics
            Gem-Quality Synthetic Jadeite Created at G.E.
            Russian Hydrothermal Synthetic Emeralds
Announcements
            102-ct Light Yellow Ashberg Diamond Currently on Display in Los Angeles
            Tiffany Iris Corsage and Other Important Jewelry in Traveling Exhibition
            Tucson Gem and Mineral Society’s 31st Annual Show Set for Tucson
            Third Annual Meeting of the Association of Women Gemologists
            ICA to Sponsor a Colored Gemstone Congress in Idar-Oberstein
            22nd Burma Gem, Jade and Pearl Emporium Will Be Held in February 1985
            Australian Jewelry Fair Will Be Held in Sydney February 16-20, 1985
            Dates Announced for 1985 Basel Fair, Switzerland

To view the full section, download the PDF above. @topic:8


Publish Year: 1984 Title: Fall 1984 Gem News International Abstract: Diamonds
            Australia: Indian Cutters Report Problems Working with Australian Diamonds
            Guinea: Aredor Diamond Mine Goes to Full Production This Year
            India: More Than 400,000 People Employed in Diamond Cutting in India
            Kenya: Government Issuing Geological Prospecting Licenses to Foreign Companies
Colored Stones
            New Molten Glass Filler Used to Seal Corundum Voids
            Update on Use of Borax in Heat Treatment in Thailand
            Gem Auction in Pakistan Raises Issues of Illegal Mining and Smuggling
            High-Grade Manganese Ore found in Orissa, India
            MMTC Activities in India Enumerated
            Zambia Cancels Emerald-Mining Contract with Saudi Arabian Company
Precious Metals
            New Platinum Prospect Located in East Transvaal, South Africa
            Ghana Plans to Resurrect Its Gold-Mining Industry
            Mitsubishi Metal Corp. Discovers Promising Gold Vein at Yatani Mine
            New Gold and Silver Reserves Discovered at Knob Hill in Republic, Washington
            Soquem and New Pascalis Mines Announce Gold Reserve East of Quebec
            Independent Miners in the Philippines Establish a Gold Town
            Plans Are Announced to Develop an Open-Cast Gold Mine in Southwest Zimbabwe
Synthetics and Simulants
            Jewelers Vigilance Committee Augments Rules on Pearl Definitions
            Iimori Lab Donates Five Interesting Glass Samples to Gems & Gemology
Announcements
            Two Major New Additions Help Mark the Centennial of the National Gem Collection
            Society of Jewellery Historians of the British Museum Announces New Annual Journal
            AGA 1985 Conference Will be Held February 4 & 5 in Tucson
            GIA Slide Library Solicits Labeled Slides of the World’s Gemstone Localities

To view the full section, download the PDF above. @topic:11


Publish Year: 1984 Title: Summer 1984 Gem News International Abstract: Diamonds
            Brazil: Large Yellow Diamond Found at Coromandel
            India: First Phase of Nationwide Exploration Program Implemented
            Philippines: First Diamond-Cutting Factory Established near Manila
            Singapore: New Diamond Exchange Operational
Colored Stones
            Three New Emerald Deposits Found in Pakistan
            Gem-Quality Amethyst Rediscovered in Rhode Island, U.S.A.
            Companies Prospecting for Emeralds, Precious Minerals in Zambia
            Tanzanian Government Announces New Mining Policy
            Significant Concentrations of Beryllium Discovered in Northwest Territories
            Chrysoberyl Found in Reworked Locality in New York, U.S.A.
            Gemologically Interesting Silica Gems Discovered in Serbia, Yugoslavia
Precious Metals
            Hemlo, Ontario Area Promises to Be Important Source of Gold
            Gold-Bearing  Zone Found Near Quebec
            OK Gold Mine in Papua, New Guinea, May See Production Begin This Year
            Exploratory Drilling at Reid Mine in Northern California Reveals High Gold Values
Announcements
            Sekikazu G. Nakakura Wins 1984 George A. Schuetz Design Contest
            Geo-Literary Society Formed at Tucson
            International Exhibition (BIJORHCA) To Be Held Sept. 7-11 in Paris
            GIA GemFest ’84 Will Be Held in Santa Monica August 21 & 22

To view the full section, download the PDF above. @topic:2


Publish Year: 1984 Title: Spring 1984 Gem News International Abstract: Diamonds from Africa
            Companies Join Forces to Mine Diamonds in Guinea
            Exploration off Namaqualand
            Government of Swaziland Grants License for Exploration
Diamonds from Australia
            Findings at Limestone Creek, Western Australia
            First Argyle Diamonds Sold in Antwerp
Diamonds from India
News of the Famous Eureka Diamond
Colored Stones
            Correction: Brazilian Amethyst
            Gem Exploration in Southern India
            Heat Treatment in Sri Lanka
            Korean Amethyst
Precious Metals
            Lady Bountiful Looks Promising
            Rich Gulch California Gold
            Soviets Recover Gold from Industrial Waste
            French Study of Worldwide Gold Deposits Now Available
Synthetics
            Seiko Growing Synthetic Gemstones by the Floating-Zone Method
Announcements
            Smithsonian Revises Gemstone Donation Procedure
            Fifth Annual Course in Antique Jewelry and Gemstones
            Entry Forms for First Ever National Competitive Exhibition Available
            Noted speakers at AFMS/CFMS Gem & Mineral Show in San Diego

To view the full section, download the PDF above. @topic:8


Publish Year: 1983 Title: Winter 1983 Gem News International Abstract: Diamonds
            Australia: First Consignment of Rough Sold through Central Selling Organization
            The CSO Starts a Quarterly Journal
            Improvement Expected in the World Diamond Market
            Japan Removes Import Duty on Diamonds
            Le Grand Coeur d’Afrique
Colored Stones
            India Puts a Ban on Rough Gem Exports
            Opal Production Falls 60% in Australia
            Yogo Sapphire
            Zoisite from Sri Lanka
Synthetics and Stimulants
            More Information on C-Ox
            Synthetic Diamond
Miscellaneous
            New French Postage Stamp for Collectors
Announcements
            Accredited Gemologists Association Meets in Tucson
            American Gem Society Celebrates its Golden Jubilee
            American Gem Trade Association Holds Gemstone Congress
           30th Annual Gem and Mineral Show in Tucson
            Reward Offered for Info about Stolen Jewels in Santa Barbara
            Necklace Featured on G&G Fall 1982 Cover Stolen in Los Angeles
Exhibits
            American Museum of Natural History

To view the full section, download the PDF above. @topic:8


Publish Year: 1983 Title: Fall 1983 Gem News International Abstract: Diamonds
            Australia: First Commercial Sale of Argyle Diamonds in Perth
            Belgium: Exports of Polished Goods Increases 6.3%
            Israel: Exports and Imports Up; More Use of Open Market Sources
            Thailand: Leaders Pledge to Make Bangkok a Major Diamond-Cutting Center
            U.S.: Diamond Mining in Colorado; NY Industry Associations; GE Synthetic
            Zaire: Returns to CSO System for Two Years
Colored Stones and Organic Materials
            Amethyst: Recent Find in Minas Gerais
            Blue Chalcedony: Namibian Mine Resumes Production
            Coral: Asian Coral is Being Gathered in Increasing Quanity
            Idocrase: New Source of Californite Promises Abundant Material
            Malachite: Reduction in Availability Due to Rigorous Regulations
Synthetics
            Cat’s-Eye Chrysoberyl:  Successful Synthetic Claimed by Japanese Company
Exhibits
            Cooper-Hewitt Museum
            Smithsonian National Museum of Natural History/Thomas M. Evans Gallery
            Smithsonian National Museum of African Art
Announcements
            $20,000 Reward Offered for Info on Houston Stolen Gems
            Bangkok Seminar on Diamond and Simulants
            AGTA Holds Third Annual Meeting In Tucson
            Tucson Gem & Mineral Society Holds 30th Annual Show

To view the full section, download the PDF above. @topic:8


Publish Year: 1983 Title: Spring 1983 Gem News International Abstract: Diamonds
            Australia: Argyle Diamond Sales Ltd Will Market Argyle Stones
            Belgium: Imports into Antwerp Increase
            Botswana: New Sorting Headquarters Opened
            China: Discovery of 96.94-ct. Stone
            Guinea: Production Scheduled to Start
            Israel: Net Imports Rise
            Japan: Customs Duty on Polished Diamonds Abolished
            Portugal: Report on Illicit Trading
            Singapore: Polishing Plant Completes First Year
            South Africa: Large Diamond Recovered
            U.S.: Crater of Diamonds State Park
            Venezuela: Annual Output Dropping
Colored Stones
            Cat’s-eye Chrysoberyl Discovered in Zimbabwe
            New Equipment Improved Cutting Efficiency of Emeralds
            Japan’s Export of Pearls Decreased
            Amethyst Deposit Discovered in Brazil
            Discovery of another Rare Taaffeite
            Irradiated Topaz from Brazil
            Southern California Mine Produces Many Colors of Tourmaline
            Synthetic Ruby Will Soon be Marketed
Tucson, 1983

To view the full section, download the PDF above. @topic:8


Publish Year: 1982 Title: The Chanthaburi-Trat Gem Field, Thailand Abstract: With the recent drastic decline in production from the classic ruby mines of Burma, Thailand has become the world's major source of gem ruby. The majority of the ruby production, as well as some significant sapphire production, comes from the provinces of Chanthaburi and Trat in southeastern Thailand. This article reviews the geology of these alluvial deposits and describes the wide range of methods used to mine the corundum. Gemologically, the Thai rubies are distinguished by their violet overtone, inhibited fluorescence, and characteristic inclusions. Also discussed is the heat treatment of corundum to enhance color, which has become a major industry in Chanthaburi. The newest product, "golden" sapphire, is examined, including the apparent stability of the color produced and clues to the detection of the heat treatment. @topic:9


Publish Year: - Title: Winter 2012 Gem News International Abstract: Colored Stones and Organic Materials
            Naturally Healed Fractures in Ethiopian Opal
            New Supplier of Montana Sapphires
Pinctada Margaritifera Cultured Pearl with Baroque-Shaped Nucleus
            Update on Ruby Mining and Trading in Northern Mozambique
Conference Report
            2012 NAG Institute of Registered Valuers Conference

To view the full section, download the PDF above. @topic:9


Publish Year: - Title: Fall 2012 Gem News International Abstract: Colored Stones and Organic Materials
            Beryl from Kaduna State, Nigeria
            Green and Orangy Yellow Calcite from Pakistan
            Citrine from Zambia
            Emerald from Ethiopia
            Emerald from Sumbawanga, Tanzania
            Gold in Trondhjemite Matrix Rock
            Hemimorphite from China
            Update on Some Mogok Gem Mines and Markets
            Rainbow Moonstone from Madagascar
            Yellow Muscovite from Brazil
            Blue Opal from Arizona Showing Play-Of-Color
            Yellow Opal from West Africa
            Quartz with Green Rutile Inclusions
            Quartz from Tanzania with Red Epidote-Piedmontite Inclusions
            Unusual Trapiche Sapphire
            Stichtite-Dominated Intergrowths with Serpentinite from Tasmania
            Zoisite from Pakistan
            Pink to Purple Zoisite from Merelani, Tanzania
Synthetics and Simulants
            Artistic Cutting of Russian Synthetic Moissanite
            “True” Red Synthetic Spinel Grown By a “Pulled” Technique in Russia
Miscellaneous
            Automated Colored Stone Cutting

To view the full section, download the PDF above. @topic:2


Publish Year: 1990 Title: Spring 1990 Gem News International Abstract: Tucson ‘90
            Beryl Triplet Cabochons
            Diffusion-Treated Corundum
            Star Ekanite
            Cat's-Eye Iolite
            Mother-of-Pearl Cameos
            Dyed Green Quartzite
            New World Sapphires
            Cat's-Eye Spinel
            Red Taaffeite
            Treated Paraiba Tourmalines
            Tanzanian Zircon
Diamonds
            Filled Diamond Update
            Computer Technology Enhances New Diamond Sorter
            Kimberlites Discovered in Canada
            Israeli-Japanese Joint Diamond-Polishing Venture
            Ghana Considers Private Mining
            Australians Develop New Technology for Diamond Exploration
Colored Stones
            New Amethyst Discovery in the Eastern United States
            Beryl Discovery in Finland
            New Find of Orthoclase
            California Star Quartz
            East African Spinels
            Oregon Sunstone Update
            Largest Known Faceted Liddicoatite Tourmaline Reportedly Found in Brazil
            Unusual Iridescent Zircon
Synthetics and Simulants
            Glass Imitation Emerald Crystal
            New Synthetic Ruby

To view the full section, download the PDF above. @topic:8


Publish Year: 1982 Title: Summer 1982 Gem News International Abstract: Diamonds
            Australia: DeBeers CSO to Market Ashton Join Venture Stones
            Botswana: Depressed Market Creates Severe Economic Problem
            Ghana: Only Producing Mine Continues through U.S. Loan
            India: Government Plans to Increase Domestic Supplies
            Israel: Customs Duty Removed
            Lesotho: Mine Closure Due to Recession
            Namibia: Production Reduced
            South Africa: Coping with Depressed Market
            U.S.: West Coast Club Opens
            Zaire: Substantial Drop in Production
Emerald
            Australia: Aga Khan Mine Output Stockpiled
            Brazil: Superior Color Discovered
Pearl
            Japan: Concern About Chinese Freshwater Pearls
Topaz and Peridot Jewelry Suite Currently on Display at GIA

To view the full section, download the PDF above. @topic:8


Publish Year: 1982 Title: Spring 1982 Gem News International Abstract: Diamonds
            Australia: Ashton Mining Predicts Yield
            Belgium: Concern over Cut Diamonds from Russia
            Ghana: Only Production Mine May Be Closed
            Guinea: Investment for Production Planned
            India: New Sources for Rough Sought
            Israel: Processing appears to be Reviving
            South Africa: Bourse Opened Recently
            Sweden: First Discovery in Europe
            Taiwan: Plant Opening in Republic of China
            U.S.: GE Announces Invisible ID
            USSR: First Underground Mine Underway
Colored Stones
            Aquamarine from Afghanistan
            Synthetic Amethyst
            Imitation Opal
            Israeli Emerald Industry
            Another Taaffeite
            New Pala Tourmaline Pockets
International Gemological Symposium
Tucson Gem and Mineral Show
            Beryl: Aquamarines Plentiful
            Corundum: Orange, Pink, Yellow Sapphires Abundant
            Garnet: Orange Garnets and Rhodolites Plentiful
            Malachite: Many Fine Specimens
            Pearl: Large Quantity on Display
            Peridot: Fine Specimens from Burma and Arizona
            Spinel: All Colors Plentiful
            Spodumene: Afghanistan Rough, Brazilian Cut
            Sugulite: Purple Stone Shown in Quantity
            Tanzanite: Few Fine Specimens in Evidence
            Topaz: Concern over Radiation
            Tourmaline: Green from Zambia Plentiful
Announcements
            Canadian Gemmological Association Opens Course
            Scholarships Offered

To view the full section, download the PDF above. @topic:8


Publish Year: 1981 Title: Fall 1981 Gem News International Abstract: Diamonds
            Angola: Highest Output Reached
            Australia: Argyle Mine to Begin Operation in 1985
            Botswana: New Mine to Begin Production in 1982
            Lesotho: Joint Project with Canada
            U.S.: Record-Setting Stone Discovered
            USSR: New Mine in Yakut Area
Pakistan Enters the Gem Scene
            Emerald: Fine Specimens from Swat
            Ruby: Abundance, Range of Color
            Spinel: Associated with Rubies
            Topaz: Deposit of Rare Color Depleted
            Aquamarine: Great Quantity Beneath K2
            Chrome Diopside: Cat’s-Eye Effect
            Kunzite: Found in Chitral
            Garnet: Pyrope Found Near Dir
            Chrome Tourmaline: Samples Too Small for Use as Gemstones
            Ornamental Gems: Occur Widely Throughout Country
Exhibits
            American Museum of Natural History
            Arizona-Sonora Desert Museum

To view the full section, download the PDF above. @topic:2


Publish Year: 1981 Title: Summer 1981 Gem News International Abstract: AGS Conclave '81
Argentine Rhodochrosite
Australian Developments
            View Toward Gem Cutting
            Diamond
            Emerald
            Sapphire
U.S. Peridot
Zaire Breaks With DeBeers
Exhibits
            Los Angeles County Museum of Natural History
            Smithsonian Institution National Museum of Man
            American Museum of Natural History

To view the full section, download the PDF above. @topic:8


Publish Year: 1981 Title: Spring 1981 Gem News International Abstract: Afghanistan Situation
Diamond
            Australia: Industrial-Quality Finds
            India: Countrywide Exploration Announced
            China: Sino-German Trade Agreement
            U.S.: Wyoming Exploration
            USSR: Record Stone Discovered
Ruby
            Kenyan Discovery
            Australian Yield
            Southern Indian Deposit
            Large Pakistan Deposits
Sapphire
            Kashmir, India, Production May Return
            Deposit in Australia Yields Large Stones
Sri Lanka Lapidary
Tuscon Gem and Mineral Show
            Aquamarine from Idaho
            Red Beryl from Utah
            Synthetic Red Beryl Only Pink
            Sugilite from Manganese Mine Prominent
            Pink Fluorite from Peru
            Topaz in Great Abundance
Exhibits
            Carnegie Institute's Museum of Natural History
            Denver Museum of Natural History
            Lizzadro Museum of Lapidary Art
            Los Angeles County Museum of Natural History

To view the full section, download the PDF above. @topic:2


Publish Year: 2014 Title: Books: Gem Identification Made Easy Abstract: By Antoinette Matlins and A.C. Bonnano, 378 pp., hardcover, illus., publ. by GemStone Press, Woodstock, VT, 2013. US$38.99.

              Originally published in 1989, Gem Identification Made Easy caters to a very broad audience of gem enthusiasts. It serves to inform and educate inexperienced gemologists, a good reference tool for seasoned veterans. Overall, this book contains a wealth of valuable information on simple, practical testing methods, written in a concise, easy-to-understand style.

Many tips and tricks for detecting treatments and how to differentiate between natural and synthetic materials are covered. Of particular interest in this latest edition is a section dedicated to identifying glass-filled rubies, which have plagued the market in the last few years. This chapter will clearly help even novice gem buyers and sellers avoid a costly mistake regarding this material.

However, this book lacks in the same measure of detail regarding diffusion treatment of corundum, which is at least as problematic in the gem trade as glass-filled rubies. The other area where it falls a bit short is image quality. Although color plates are included in this version, the images are small and in some cases very poor illustrations of their intended subjects. Most of the instructional images throughout the text are otherwise adequate.

Overall, this is a welcome addition to any gemological library, especially for the gemologist who must rely on portable instruments. If you’re in search of a “how-to” book full of vibrant images, this is not the one for you. If you are a gemologist at any level in need of a practical guide to gem testing or a reference guide, then you will be quite satisfied with this book. @topic:8


Publish Year: 2014 Title: Books: Smithsonian Nature Guide on Gems Abstract: By Ronald Louis Bonewitz, 224 pp., illus., DK Publishing, New York, 2013. $14.95.

              As part of the Smithsonian Nature Guide series, Gems has the look and feel of a field guide or a lab manual. The book is durable enough to serve these purposes, and the technical information contained within lends itself to such use on a limited basis. Although licensed by the Smithsonian Institution and featuring some images from its collection, this book is largely a British product, using terms that are more common among gemologists from the United Kingdom and Europe.

The 34-page introduction serves as an overview of gemology, including such topics as gem formation, classification, cutting, enhancements, synthetics, and history and folklore. The book’s only other section, “Gemstones,” includes segments on precious metals and organics and a glossary, but the largest entry is “Cut Stones.” Here, the various gems are arranged much in the style of a mineralogical text, divided by chemical composition. Sections cover the native elements, sulfides, silicates, and tungstates; based on that system, the cut gems are sometimes are presented out of the order anticipated by someone with a working knowledge of Dana’s System of Mineralogy and Dana’s Textbook of Mineralogy. It should also be noted that the book does not further divide the silicates into categories such as soro-silicates or tekto-silicates. For each featured cut gem, precious metal, and organic gem, there is a profile box detailing its basic properties and, where appropriate, the typical cutting styles. The basic chemical formula is given, along with the name origin, formation and source information, and color images, including examples of rough material.

One of the book’s merits is ease of use, with its portable format and easily located vital information. It contains far more gem materials than most comparable books, opening up a whole new world of gems to the consumer. Another virtue is the profusion of color images used to illustrate various aspects of the gemstones. I applaud the “Gem Enhancement” section: To make an informed purchase, the consumer needs to be aware of methods to improve the appearance, durability, and value of a gem material.

Some areas could use revision. The reader is given no sense of the author’s qualifications to write about gemstones. Another issue concerns the use of the outdated terms “precious” and “semi-precious.” Why should the negative connotation of “semi-precious” be applied to such wonderful gems as alexandrite or red spinel, which often sell for at least as much as those traditionally labeled “precious?” I was surprised that beryl, rather than topaz, was used to illustrate a hardness of 8 on the Mohs scale, and disagreed with the assertion that soft stones are cut only for collectors. This may have been true in the past, but with the recent boom in at-home shopping, softer stones such as fluorite are being purchased by a great many consumers. It is important to inform consumers of the care required for softer gems without chasing them away. The color images, while numerous, do not always convey the actual color of the gem. In many of the photos, lines are used to point out a particular aspect of the gem, such as fire or doubling, yet in some instances you can’t see that feature.

Finally, I found some faulty information. The most conspicuous inaccuracy is the statement that flux-melt gemstones, including some synthetic emeralds, leave curved growth zones. The reality is that curved growth zones are mostly associated with flame-fusion synthetics, which do not include synthetic emerald. Flux-melt synthetic emeralds are known for showing angular growth features. There are other inaccuracies of various degrees that could be addressed, but I do not wish to create too negative an impression.

Despite some outmoded terminology and factual errors, this attractive book’s numerous gemstones, helpful illustrations, portability, and low price make it worth purchasing, especially for the general consumer. @topic:2


Publish Year: - Title: Books: Smithsonian Nature Guide on Gems Abstract: By Ronald Louis Bonewitz, 224 pp., illus., DK Publishing, New York, 2013. $14.95.

                      As part of the Smithsonian Nature Guide series, Gems has the look and feel of a field guide or a lab manual. The book is durable enough to serve these purposes, and the technical information contained within lends itself to such use on a limited basis. Although licensed by the Smithsonian Institution and featuring some images from its collection, this book is largely a British product, using terms that are more common among gemologists from the United Kingdom and Europe.

The 34-page introduction serves as an overview of gemology, including such topics as gem formation, classification, cutting, enhancements, synthetics, and history and folklore. The book’s only other section, “Gemstones,” includes segments on precious metals and organics and a glossary, but the largest entry is “Cut Stones.” Here, the various gems are arranged much in the style of a mineralogical text, divided by chemical composition. Sections cover the native elements, sulfides, silicates, and tungstates; based on that system, the cut gems are sometimes are presented out of the order anticipated by someone with a working knowledge of Dana’s System of Mineralogy and Dana’s Textbook of Mineralogy. It should also be noted that the book does not further divide the silicates into categories such as soro-silicates or tekto-silicates. For each featured cut gem, precious metal, and organic gem, there is a profile box detailing its basic properties and, where appropriate, the typical cutting styles. The basic chemical formula is given, along with the name origin, formation and source information, and color images, including examples of rough material.

One of the book’s merits is ease of use, with its portable format and easily located vital information. It contains far more gem materials than most comparable books, opening up a whole new world of gems to the consumer. Another virtue is the profusion of color images used to illustrate various aspects of the gemstones. I applaud the “Gem Enhancement” section: To make an informed purchase, the consumer needs to be aware of methods to improve the appearance, durability, and value of a gem material.

Some areas could use revision. The reader is given no sense of the author’s qualifications to write about gemstones. Another issue concerns the use of the outdated terms “precious” and “semi-precious.” Why should the negative connotation of “semi-precious” be applied to such wonderful gems as alexandrite or red spinel, which often sell for at least as much as those traditionally labeled “precious?” I was surprised that beryl, rather than topaz, was used to illustrate a hardness of 8 on the Mohs scale, and disagreed with the assertion that soft stones are cut only for collectors. This may have been true in the past, but with the recent boom in at-home shopping, softer stones such as fluorite are being purchased by a great many consumers. It is important to inform consumers of the care required for softer gems without chasing them away. The color images, while numerous, do not always convey the actual color of the gem. In many of the photos, lines are used to point out a particular aspect of the gem, such as fire or doubling, yet in some instances you can’t see that feature.

Finally, I found some faulty information. The most conspicuous inaccuracy is the statement that flux-melt gemstones, including some synthetic emeralds, leave curved growth zones. The reality is that curved growth zones are mostly associated with flame-fusion synthetics, which do not include synthetic emerald. Flux-melt synthetic emeralds are known for showing angular growth features. There are other inaccuracies of various degrees that could be addressed, but I do not wish to create too negative an impression.

Despite some outmoded terminology and factual errors, this attractive book’s numerous gemstones, helpful illustrations, portability, and low price make it worth purchasing, especially for the general consumer. @topic:2


Publish Year: 1962 Title: Developing the Powers of Observation in Gem Testing Abstract: According to Richard Liddicoat, the critical thinking process necessary for gem identification can be compared to the keen detective work of a Sherlock Homes. In this detailed look at the step-by-step procedures for pinpointing the identity of a given gem, Liddicoat stresses the importance of observation and perception. The gem identification techniques taught at GIA for more than 50 years have their foundation in these basic methods. @topic:8


Publish Year: - Title: Books: Gem Identification Made Easy Abstract: By Antoinette Matlins and A.C. Bonnano, 378 pp., hardcover, illus., publ. by GemStone Press, Woodstock, VT, 2013. US$38.99.

                      Originally published in 1989, Gem Identification Made Easy caters to a very broad audience of gem enthusiasts. It serves to inform and educate inexperienced gemologists, a good reference tool for seasoned veterans. Overall, this book contains a wealth of valuable information on simple, practical testing methods, written in a concise, easy-to-understand style.

Many tips and tricks for detecting treatments and how to differentiate between natural and synthetic materials are covered. Of particular interest in this latest edition is a section dedicated to identifying glass-filled rubies, which have plagued the market in the last few years. This chapter will clearly help even novice gem buyers and sellers avoid a costly mistake regarding this material.

However, this book lacks in the same measure of detail regarding diffusion treatment of corundum, which is at least as problematic in the gem trade as glass-filled rubies. The other area where it falls a bit short is image quality. Although color plates are included in this version, the images are small and in some cases very poor illustrations of their intended subjects. Most of the instructional images throughout the text are otherwise adequate.

Overall, this is a welcome addition to any gemological library, especially for the gemologist who must rely on portable instruments. If you’re in search of a “how-to” book full of vibrant images, this is not the one for you. If you are a gemologist at any level in need of a practical guide to gem testing or a reference guide, then you will be quite satisfied with this book. @topic:8


Publish Year: - Title: Video Feature: Gem Mining in Cambodia Abstract: See how locals in Pailin, a province in western Cambodia near the Thai border, mine for small sapphires, rubies, zircon, garnet, and sometimes gold.

	Sapphire and Ruby Mining

	GIA field gemologist Vincent Pardieu joins a small team of miners as they wash the ground for sapphire and ruby at a secondary deposit in Pailin.

	River Mining in Pailin, Cambodia

	Pardieu visits one of two main rivers in Cambodia where local miners collect garnet, zircon, ruby, sapphire, and sometimes gold from the sand. Many of them mine the river during the dry season to earn additional income. @topic:9


Publish Year: - Title: Fall Fashion Ideas: Orange Gems Abstract: Think icy sherbet…A sumptuous glass of orange juice…Stunning autumn leaves…A vivid sunset. Orange – this unexpected color is a refreshing trend. Mother Nature did some of her best gemstone work with her paintbrush dipped in orange, and this ever-appealing color is an increasingly popular choice in jewelry, too.

Orange gemstones stand out and shine, adding zest to any wardrobe. Orange gemstones are classic – they have graced fashions for centuries and are always in style.

Consider some orangey-hued gemstones: Sapphire. Garnet. Fire Opal. Topaz. Citrine. Where do they come from? What makes them special? What do they cost? Let’s take a look at a few outrageous oranges, and find out more about these gemstones from the experts at GIA (Gemological Institute of America), the world’s foremost authority in gemology.

Fancy Sapphire, a variety of the mineral corundum, features orange among many appealing hues. An especially alluring orange-pink color is called padparadscha, after the lotus blossom. GIA’s gem experts point out that this latter variety is very rare and ranges from pastels to more fiery shades. The best examples of authentic padparadscha sapphire usually command a premium price, often equal to their fine blue counterparts. Sri Lanka and East Africa are major sources of orange and padparadscha sapphire.

Spessartine Garnet is perhaps the most eye-catching orangey gemstone around. According to GIA’s colored stone experts, it is prized for its bright orangy-yellow to yellowish-orange color, with some of the best – and most sought after – examples mined in Southern California, at the Little Three mine, near Ramona. High-qualilty spessartine has more recently been mined in Namibia and Nigeria.

Mandarin Garnet is a trade name for bright orange spessartine from Namibia. Although relatively inexpensive in small sizes, larger stones (which rarely exceed 10 carats) can fetch significant prices. The rich color of Mandarin garnet makes it a favorite of orange gemstone lovers worldwide.

Fire Opal is an anomaly in the opal family. Opals are usually smoothly polished in a cabochon (domed) shape, mined in Australia, and are opaque (not see-through). But the intriguing fire opal is often found in a fabulous orange color, cut in a faceted manner, mined in Mexico, and is mostly transparent in better quality facet-grades. And it’s also found at favorable prices in jewelry this season.

Topaz is another gemstone that is found in various colors, such as yellow, dark blue, pink, red, and light green, but it truly shines in orange. Fine orange and “imperial topaz” (orange with a hint of red) are among the rarer colors of topaz, and their higher prices reflect their scarcity. This unusual shade is mostly found in Brazil.

Citrine, a variety of the mineral quartz, can appear in an orange shade, called Madeira, although it’s most often seen in one of its yellow coats. Mined mainly in Brazil, citrine is often found in larger sizes, due to its affordable price, and it is easy to find.

There’s no right or wrong when choosing an orange shade or a type of jewelry. Whether your passion is a big pair of earrings in citrine or topaz, a fire opal brooch, a mandarin garnet pendant, or a sapphire centered in a ring, this season’s best look for you could be in shades of orange.

When shopping for gemstones, look for a jeweler who is a Graduate Gemologist or Graduate Jeweler. GIA also offers identification reports on gemstones, including those discussed here, to verify their authenticity. @topic:2


Publish Year: - Title: 2017 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design Showcases Jewelry Art Abstract: This close up of the pendant on Catherine Zheng’s Art Deco-inspired necklace showcases the blue sapphire, tanzanite, diamonds and enamel she used in her design.

Judges for the first annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design were surprised when they saw the display of original hand-painted renderings from GIA's Jewelry Design Certificate program students on display in Tucson recently.

“The judges were so surprised. They walked in and said ‘Wow,’” Elizabeth Brehmer, director of GIA’s Jewelry Manufacturing Arts (JMA) program, said. “The renderings are really lifelike and executed at the right size and scale. They are colorful and lively and really jump off the page.

“There is a life to something that you render and paint,” she said. “There’s something very personal, organic and real about it.”

The Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design competition was created to inspire and encourage beginning jewelry designers and celebrate the long history of hand-sketched and painted jewelry art for which Gianmaria Buccellati was known.

“Mr. Buccellati always protected his brand and ensured that the things that came out of his workshop were unique, special and always maintained a very high standard," Brehmer said. "Having a competition with the foundation’s name attached to it really speaks volumes to recognizing the work GIA student finalists provided for the judging.”

The competition was open to individuals who successfully completed the 2017 Jewelry Design Certificate program at any GIA school worldwide. The students' original works of art go through a couple of different gates of judging, according to Brehmer. First, they complete the course and showcase their work to their peers at each of the schools, then the paintings are submitted to a committee in Carlsbad to make sure they meet all of the standards and criteria taught at GIA. This year, 12 global design courses were offered and one student from each course at each school (Carlsbad, Hong Kong, India, New York, London, Taiwan and Thailand) was selected to participate.

Along with an original rendering, each entry had a material statement and an inspiration statement.
“The material and inspiration statements are a significant part of the concept and execution of the rendering – and are a critical part of the judging in the final round,” Brehmer said. “Their compelling inspiration stories contributed to their art.”

Zheng with Larry French, chief officer of North American strategies for the Gianmaria Buccellati Foundation, who will help her plan her trip to Italy. Photo by Kevin Schumacher/GIA
Brehmer said this type of competition is important for GIA students to participate in because it gives them a chance to showcase their designs to experts in jewelry design.

“The students were so excited when the announcement about the competition was made,” Brehmer said. “There’s not another competition out in the market that allows them to showcase the skills they learn as an artist and as a designer when they go through a jewelry design program at GIA, anywhere in the world.”

A panel of five industry experts from a variety of aspects of jewelry design did the final judging the morning of the “Party at the GIA Gem Mine” alumni event in Tucson: Molly Bell, executive vice president of Rio Grande Tools & Supplies; Remy Rotenier, president of Remy Design and a jewelry designer and educator; Ginger Porcella, chief curator of the Tucson Museum of Contemporary Art; Alishan Halebian, owner of Alishan, a retail and custom design-curated company; and Victoria Gomelsky, editor-in-chief of JCK magazine.

Doug Hall, a senior instructor in GIA’s JMA program, provided an overview of GIA’s Jewelry Design Certificate program to the judges before they began the process of selecting a winner, including what students learn, how they learn it, the perspective they are asked to employ, and the techniques they use.

Brehmer said the judges were impressed by the quality of the GIA students’ work and were thrilled they could pick the renderings up to examine them and then read the student’s comments on what inspired them and the materials they would use make the piece.

“The judges said they rarely get to see original renderings and several commented on the time and effort that went into this type of work. One judge noted that it really afforded an opportunity to close a sale quicker because the customer would see what something was really going to look like,” she said. “That was an interesting dialogue between the judges, because it’s a very traditional method [painting renderings] that you can apply in today’s industry.”

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The grand prize winner of the competition – Catherine Zheng – was announced during a formal presentation at the alumni event. Her platinum and tanzanite Art Deco-style necklace impressed the judges with its elegance, beautiful rendition and the fact that it could be manufactured, Brehmer said.

Zheng, a Los Angeles area real estate broker for high-end clients, was “totally shocked” when her name was announced as the grand prize winner.

“I never thought that I'd win this competition because I know there are many students in the jewelry design course who are very talented – and a lot of them either studied art in college or they already have a jewelry industry background,” she said.

Zheng said she makes a good income in real estate, but always felt like something was missing in her life.

“I was really into art while I was in high school and I earned multiple art rewards, such as the National Award for Creative Artists and a Special Congressional Recognition in ‘An Artistic Discovery.’ My dream was to become a designer, but my family, like many traditional Asians, thought it was too risky to become an artist,” she said.

So Zheng studied finance and marketing in college and become a banker and then a real estate broker after she graduated. She said her creative art ideas kept pulling at her, however, so she signed up for the Jewelry Design Certificate program course in Carlsbad. Hall, who she calls “awesome,” was her instructor.

“Doug is a perfectionist and I really learned a lot by his high standards,” she said. “The course is only nine weeks long, but we learned so much about technique and skills during this short period of time. Not only that, the second half of the course gives the students a lot of room to be creative.”

Catherine Zheng’s Art Deco-inspired necklace features blue sapphire, tanzanite, diamonds and enamel. An ornate pendant hangs from a chain with stations of embellished links in between the chain.
Zheng continued to work her real estate business while she took the course.

“The challenging part was that I had to work at night after my day job and could only sleep four to six hours every day to fit it all in,” she said. “I haven't drawn for more than 10 years, but I'm very glad that I put in my best effort while studying.”

She said all of the hard work is extremely rewarding. “It really feels great to win when you didn't expect it,” she said.

Beyond the recognition Zheng received as grand prize winner, she will go on a one week all-expense paid trip to Florence to take in Renaissance art and view part of the jewelry collection of Gianmaria Buccellati housed in the Pitti Palace. She will also travel to Milan and have the opportunity to meet Mrs. Buccellati, where she will receive a plaque acknowledging her as the winner of the competition.

“I'm super excited to go to Italy. I have been there a few times before, but this is sure to be the most exciting and memorable trip,” she said. “I am very much looking forward to meeting Mrs. Buccellati.”

Zheng said winning the Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design has inspired her to continue to pursue her professional jewelry design dreams – which is exactly why it was created – and she plans to study CAD/CAM design and become a GIA Graduate Gemologist in the near future.

“I'm definitely looking into starting my career as a jewelry designer or even my own line of jewelry,” she said. “This means so much to me as a beginning designer and it really gives me a lot of encouragement and faith to continue on this career path.” @topic:6


Publish Year: 2020 Title: Pink Sapphires from Madagascar, Rose-Cut Colored Stones from the Baroque Era, Separating Blue Amber Localities, and More… Abstract: Welcome to the Winter 2020 issue of Gems & Gemology! This issue brings an exciting conclusion to the volume year with a study on low-temperature heat treatment of pink sapphire, a characterization of rose cuts that adorn rare artifacts of a bygone era, and the means to separate the three principal localities for blue amber.
“A characterization of rose cuts that adorn rare artifacts of a bygone era…”
In the lead article, a team led by Sudarat Saeseaw examines the effects of low-temperature heat treatment on inclusions in pink sapphire from Ilakaka, Madagascar. The detailed characterization of these samples before and after heating will help laboratories develop treatment detection criteria. This study also presents a useful technique using Fourier-transform infrared (FTIR) spectroscopy to detect low-temperature heat treatment of this material.
In the second article, researcher Karl Schmetzer returns to the pages of G&G with an evaluation of seventeenth-century colored stones fashioned as rose cuts, which richly decorate rare artifacts once belonging to archbishops and prince-electors of Trier and Cologne. This article seeks to fill a gap in the historical record, as rose-cut colored stones have been mainly overlooked in favor of their diamond counterparts.
Next, Zhiqing Zhang and a team from the Gemmological Institute, China University of Geosciences in Wuhan use observation, UV-Vis-NIR spectroscopy, and excitation-emission mapping to separate blue amber mined from the Dominican Republic, Mexico, and Myanmar. This widely loved organic gemstone may be grouped according to very strong blue fluorescence and distinct emission and excitation wavelengths.
In the final article, Doan Thi Anh Vu from Vietnam National University heads an investigation of mineral inclusions in basaltic sapphire from southern Vietnam. The team analyzes inclusion chemistry using EPMA to understand the formation model of these sapphires in relation to the basaltic volcanism of this locality.
As always, our regular columns feature an array of interesting gemological findings. Highlights of from Lab Notes include a large “all-American” diamond from Arkansas and artificial glass prisms masquerading as Paraíba tourmaline. Micro-World enchants with the inner beauty of gems: lazurite and snowflakes in Burmese ruby from Mogok and Mong Hsu, respectively, and sapphires exhibiting elongated rutile. Stay up to date in the Gem News International section with a new emerald locality in Southern California and the use of rhodium plating on etched iron meteorites. Diamonds from the Deep returns with a unique perspective on how diamond ages can help us understand continent evolution spanning billions of years.
Finally, we include a reprint of the Spring 2020 article by Emily Dubinsky et al. (“A Quantitative Description of the Causes of Color in Corundum”) to correct the color of several photos and areal color density circles. We regret these errors and have used the opportunity to produce a new wall chart displaying the corundum chromophores from this article.
We hope you enjoy our Winter issue! @topic:2


Publish Year: 2024 Title: Trigon Party on a Diamond Abstract: A collection of trigons on the pavilion surface of a round brilliant-cut diamond. Photomicrograph by Isabelle Corvin; field of view approximately 2.0 mm.
Triangular-shaped markings known as trigons are common in natural diamond. These “birthmarks” formed during growth are signs of a diamond’s ancient origin deep within the earth. The trigons in the figure above form a striking cluster on the faceted girdle and extend into two of the lower girdle facets of a 1.01 ct natural diamond. Even through the cutting and polishing process, these trigons remained on the surface.
Although trigons are not exceedingly rare, the assortment of this many trigons grouped together provides a remarkable portrait created by Mother Nature. The perfection of a diamond is on full display in the angles, luster, and alignment of each trigon. @topic:4


Publish Year: 2024 Title: Stellate Cloud in Diamond Abstract: This patchy cloud with an uneven distribution of pinpoints observed in a natural diamond appears to depict a celestial star. The image was captured in monochrome. Photomicrograph by Tejas Jhaveri; field of view 2.9 mm.
Impurity clouds in diamonds occur in a variety of forms such as scattered, planar, or patchy clouds. The author recently observed one such cloud with an unusual morphology in a 1.51 ct natural diamond with E color and SI2 clarity (see above). This remarkable cluster of pinpoints took the form of a four-point star. This celestial inclusion is sure to be seen as a lucky charm. @topic:4


Publish Year: 2023 Title: Distinctive Feather in Diamond Abstract: A feather in a 0.30 ct diamond with I1 clarity resembled an alligator. Photomicrograph by Raju Jain; field of view ~3 mm.
Recently, the authors examined a 0.30 ct type Ia diamond with D color and I1 clarity. The diamond displayed a grade-setting feather resembling an alligator (see above), which was best observed through the pavilion facets. This unusual clarity characteristic is a charming find that adds distinction to this colorless diamond. @topic:4


Publish Year: 2023 Title: Cross in Natural Diamond Abstract: A cross pattern observed in this DiamondView image of a 0.31 ct D-color type IIa diamond. Image by Priyanka Kadam.
DiamondView imaging of the 0.31 ct D-color type IIa modified round brilliant diamond shown in the figure above revealed an interesting fluorescence pattern. The image displayed blue fluorescence as well as a darker pattern in the shape of a cross. One of the pavilion main facets was longer than the other three, producing this distinct cross pattern when the diamond was viewed through the table. Depending on the specific angle of the pavilion main facets, such a distinct pattern might not be visible in the DiamondView. @topic:4


Publish Year: 2023 Title: Exquisite Butterfly in Diamond Abstract: When light reflects from this crystal in a 1.01 ct diamond, the halo resembles a colorful butterfly. Photomicrograph by Tejas Jhaveri; field of view 2.90 mm.
Examination of a 1.01 ct triangular portrait-cut diamond with E color and I2 clarity revealed an inclusion in the center of the table resembling a butterfly (see the figure above and the video below). The butterfly inclusion was composed of a crystal with a stress halo. The crystal did not break the surface and was completely enclosed within the diamond. The rough was skillfully cut in such a way that this crystal was positioned on the center of the table when polished. The play of light reflects artistically on the stress halo, creating the appearance of a colorful butterfly.

	“Butterfly” Inclusion in Diamond @topic:4


Publish Year: 2021 Title: Bicolor Rough Diamond Crystals Abstract: Figure 1. These two rough diamond crystals (1.75 ct on the left and 1.44 ct on the right) are rare examples of diamonds showing both pronounced pink and colorless sections. Field of view 10.8 mm (left) and 7.4 mm (right). Photos by Michaela Hariňová (left) and Nathan Renfro (right).

The GIA laboratory in Antwerp regularly receives pink diamond crystals for examination as part of the Diamond Origin Report. This recent service has allowed GIA researchers to study a greater number of rough diamonds in addition to their faceted counterparts. Two crystals, weighing 1.75 and 1.44 ct and both reportedly from Australia, were among those submitted. These were considered quite interesting, as they contained colorless and pink sections with distinct boundaries (figure 1).
The color in the vast majority of naturally pink diamonds is attributed to a broad absorption band at about 550 nm within the visible absorption spectrum. This band generally results from distortion of the crystal lattice from plastic deformation due to stress after crystal growth. However, much remains unknown about the actual formation and configuration of this feature. Therefore, these two crystals provide a unique chance to study natural diamond formation and the origin of pink color in greater detail.
The pink section of both analyzed samples likely experienced great stress in order to undergo the plastic deformation necessary to impart the pink color. The colorless sections were not similarly deformed so presumably they represent a different and later growth event (figure 2).

Figure 2. A close-up image of the 1.44 ct diamond crystal shows the boundary between the pink (left) and colorless (right) sections. Photo by Nathan Renfro; field of view 3.16 mm.
Visible-NIR absorption spectra collected from the pink and near-colorless sections of the diamonds show differences in the 550 nm region. Observed in the spectrum for the pink portion is the expected absorption at 550 nm, while the spectrum for the colorless portion shows a lack of absorption (figure 3, left).

Figure 3. Left: Vis-NIR absorption spectra for the 1.44 ct crystal collected from the pink and colorless sections. The 550 nm absorption band is prominently visible within the pink section. The spectra are stacked for clarity. Right: PL spectra with 532 nm excitation of the 1.44 ct crystal show a ~600–730 nm emission band collected from the areas of pink banding, which was not detected from the colorless section—this luminescence band has previously been linked with the 550 nm absorption band. The diamond Raman peaks are scaled as equal.
For the 1.44 ct crystal, we also collected infrared (IR) absorption spectra and photoluminescence (PL) spectra from both the pink and the colorless sections using 455 and 532 nm laser excitation wavelengths. The IR absorption spectra for both sections indicate type Ia diamonds with saturated concentrations of nitrogen. Due to this saturation, it was not possible to determine the total nitrogen content or the ratio of the A and B nitrogen centers, which could have helped in further distinguishing these two sections.
Within the PL spectra, the peak widths for the diamond Raman peak and the H3 peak were comparable in both the pink and colorless sections. Additionally, a PL peak at 676 nm was detected in both sections; although its configuration is unknown, it was documented previously in other rough pink diamonds (E. Gaillou et al., “Spectroscopic and microscopic characterizations of color lamellae in natural pink diamonds,” Diamond and Related Materials, Vol. 19, No. 10, 2010, pp. 1207–1220). The other notable feature detected by PL mapping was a broad (~600–730 nm) emission band (figure 3, right) that coincided with the pink banding revealed by immersion in methylene iodide (figure 4). Its detection is consistent with other pink diamonds and likely related to the 550 nm absorption band (e.g., S. Eaton-Magaña et al., “Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds,” Diamond and Related Materials, Vol. 105, 2020, p. 107784).

Figure 4. The 1.44 ct crystal was immersed in methylene iodide to reveal additional details. The red arrows within the inset (field of view 3.4 mm) indicate the pink banding. Photos by Troy Ardon.
As natural pink diamonds are quite rare, finding two examples of such bicolor crystals that show these distinct pink and colorless sections is an extraordinary find. @topic:4


Publish Year: 2023 Title: Rare Natural Bicolor Diamond Abstract: Figure 1. This 0.63 ct tapered baguette-cut diamond showed two major color zones. Photo by Adriana Robinson.
A 0.63 ct bicolor diamond was submitted to GIA at the 2023 Tucson gem show for scientific examination. Previously submitted to GIA in 2008 for a colored diamond grading report, this tapered baguette-cut natural diamond had two major color zones: Fancy Dark orangy brown and Fancy Dark brown greenish yellow (figure 1). The brown greenish yellow zone had chameleon properties, including a temporary color change upon heating or when left in darkness for an extended period of time (possibly days).  Visible narrow bands with darker color were observed within the brown greenish yellow zone (figure 1). Fourier-transform infrared spectra collected from the two color zones indicated that both were type Ia with comparable nitrogen concentrations. No amber centers or carbon dioxide absorption were detected in either color zone.
Bicolor diamonds are very uncommon, and the colors likely result from a combination of lattice defects. The major causes for yellow coloration in diamond include N3 centers, C centers, H3 centers, and the 480 nm absorption band (C.M. Breeding et al., “Naturally colored yellow and orange gem diamonds: The nitrogen factor,” Summer 2020 G&G, pp. 194–219), whereas brown coloration is typically associated with vacancy clusters produced during plastic deformation (D. Fisher, “Brown diamonds and high pressure high temperature treatment,” Lithos, Vol. 112, Supplement 2, 2009, pp. 619–624). It has been reported that diamonds rich in carbon dioxide might also have a brown color (T. Hainschwang et al., “HPHT treatment of CO2 containing and CO2-related brown diamonds,” Diamond and Related Materials, Vol. 17, 2008, pp. 340–351). Ultraviolet/visible/near-infrared spectra collected separately from the two color zones to determine their color origins indicated that both color zones contained the 480 nm absorption band. In addition to this 480 nm absorption band, the brown color zone also showed enhanced absorption extending from the near-infrared region toward the UV region of the spectrum.

Figure 2. Alternating blue and greenish yellow fluorescence zones were observed with deep-UV excitation. This fluorescence pattern is typical for diamonds colored by the 480 nm visible absorption band. Image by Stephanie Shaw.
Diamonds colored by the 480 nm absorption band generally have multiple growth zones with distinct fluorescence colors excited by deep UV (<230 nm), due to their complex multi-stage growth under changing conditions in the earth’s mantle (Breeding et al., 2020). This bicolor diamond had alternating blue and greenish yellow fluorescence zones (figure 2), similar to the fluorescence patterns in other diamonds with the 480 nm absorption band. The fluorescence zones did not correlate with the major color zoning (i.e., orangy brown and brown greenish yellow) in this diamond. However, the greenish yellow fluorescence bands (figure 2) appeared to correspond to the narrow bands with darker color in the brown greenish yellow color zone (figure 1).

Figure 3. Multiple orange inclusions were observed in this bicolor diamond. The largest was identified as pyrope-almandine-grossular garnet. Photomicrograph by Mei Yan Lai; field of view 1.76 mm.
A cluster of orange mineral inclusions was observed beneath the table facet, where the largest inclusion measured 180 μm in maximum dimension (figure 3). The Raman spectrum of the largest inclusion showed the characteristic peaks of pyrope-almandine-grossular garnet, (Mg,Fe,Ca)3Al2(SiO4)3, at 358, 558, and 917 cm–1 (e.g., E.M. Smith et al., “Raman identification of inclusions in diamond,” Reviews in Mineralogy and Geochemistry, Vol. 88, 2022, pp. 451–473), indicating the diamond was associated with eclogite host rocks having pyrope-almandine-grossular garnet as a major constituent mineral.
This unique bicolor diamond exhibiting two distinctly different colors demonstrates the variety possible within the natural world. @topic:4


Publish Year: 2023 Title: Cricket Bat Diamond Abstract: Figure 1. A 1.04 ct diamond in the shape of a cricket bat, measuring 14.20 mm long. Photo by Priyanka Kadam.
As early as the seventeenth century, the British introduced the sport of cricket to the Indian subcontinent, where it is now the most popular sport. Recently, a diamond shaped like a cricket bat (figure 1) was submitted to GIA’s Mumbai laboratory for testing. In cricket, a bat is a wooden piece of equipment with a long handle attached to a flat-fronted blade, used to hit the ball. This diamond weighed 1.04 ct and measured 14.20 × 4.12 × 2.13 mm. It had a Light brown color. The bat-shaped diamond was partially polished with a rough texture retained on the tip of the handle and the front part of the bat. According to the diamond manufacturer, the original rough skin is intentionally kept in a few parts to authenticate its natural origin.
Based on spectroscopic features, it was confirmed to be type IIa with a very weak peak at 3107 cm–1 (hydrogen-related infrared absorption peak). Photoluminescence spectra collected at liquid nitrogen temperature with varying laser excitations revealed its natural origin; no color treatment was detected. A crosshatched “tatami” strain pattern was clearly observed between crossed polarizers when viewed under a microscope.
In photoluminescence spectra collected at room temperature with 405 nm excitation, this diamond also showed the presence of N3, a defect wherein a vacancy is surrounded by three nitrogen atoms.

Figure 2. The cricketer’s name and signature inscribed on the diamond.
As shown in figure 2, this special diamond is inscribed with the name and signature of Virat Kohli, who is widely regarded as one of the greatest players in the history of the sport. The owner of the diamond intends to gift it to Kohli. @topic:4


Publish Year: 2023 Title: Carbon Dioxide in a Brown Diamond Abstract: Figure 1. This 1.03 ct natural Fancy Dark brown diamond has uneven color zoning and abundant black inclusions. Infrared absorptions corresponding to carbon dioxide (2370 and 659 cm–1) and carbonate (1433 and 870 cm–1) were detected. Photo by Mei Yan Lai.
The Carlsbad laboratory recently examined a 1.03 ct natural Fancy Dark brown diamond with uneven color zoning and abundant black inclusions (figure 1). The diamond had infrared absorption features at 2370 and 659 cm–1, corresponding to the asymmetric stretching mode and bending mode of carbon dioxide, respectively (E. Barannik et al., “Shift of CO2-I absorption bands in diamond: A pressure or compositional effect? A FTIR mapping study,” Diamond and Related Materials, Vol. 113, 2021, article no. 108280). Diamonds containing carbon dioxide are rarely submitted for diamond grading reports, and this brown diamond is one of the few GIA has encountered. Carbon dioxide likely exists as submicroscopic solid inclusions in natural diamond (M. Schrauder and O. Navon, “Solid carbon dioxide in a natural diamond,” Nature, Vol. 365, 1993, pp. 42–44). The major infrared absorption peaks observed are shifted from the peak positions of atmospheric carbon dioxide (2350 and 667 cm–1), and the peak shift depends on pressure and the presence of impurities such as water and nitrogen in the trapped carbon dioxide inclusions (Barannik et al., 2021).

Figure 2. Microscopic examination under high magnification revealed the hexagonal shape of the black inclusions. Photomicrograph by Mei Yan Lai; field of view 1.26 mm.
Carbonate-related absorptions at 1433 and 870 cm–1 were also detected. These absorptions have previously been reported in some natural diamonds containing solid carbon dioxide inclusions (e.g., Summer 2005 Lab Notes, pp. 165–167; Barannik et al., 2021). Clusters of black hexagonal inclusions were observed in the diamond (figure 2), and the individual inclusions ranged in size from <1 to ~50 μm. Similar inclusions have been documented in some carbon dioxide–bearing natural diamonds and identified as graphite platelets (A. Shiryaev et al., “Exsolution of oxygen impurity from diamond lattice and formation of pressurized CO2-I precipitates,” Carbon Trends, Vol. 11, 2023, article no. 100270).
This brown diamond containing carbon dioxide displayed yellow fluorescence when exposed to long-wave UV. When exposed to deep UV (<230 nm), the diamond exhibited irregular surface fluorescence zoning with yellowish green, bright green, and blue colors caused by distinct lattice defects. The yellow fluorescence to long-wave UV, heterogeneous distribution of lattice defects, and irregular surface fluorescence zoning under deep-UV excitation are commonly observed in diamonds colored by the 480 nm absorption band (known as “480 nm band diamonds” in the trade; C.M. Breeding et al., “Naturally colored yellow and orange gem diamonds: The nitrogen factor,” Summer 2020 G&G, pp. 194–219). In fact, the photoluminescence (PL) spectra of this brown diamond closely resembled those of 480 nm band diamonds. The most notable PL feature detected was the broad band centered at ~680 nm, which is attributed to the vibronic emission associated with the 480 nm absorption band (A. Collins and K. Mohammed, “Optical studies of vibronic bands in yellow luminescing natural diamonds,” Journal of Physics C: Solid State Physics, Vol. 15, 1982, pp. 147–158). The similarity in spectroscopic features between carbon dioxide–bearing brown diamonds and 480 nm band diamonds has been previously reported, and a genetic relationship between the two has been suggested (T. Hainschwang et al., “HPHT treatment of CO2 containing and CO2-related brown diamonds,” Diamond and Related Materials, Vol. 17, 2008, pp. 340–351). @topic:4


Publish Year: 2023 Title: Iridescent Inclusion in Brown Diamond Abstract: This iridescent ferropericlase crystal with a stress halo measuring approximately 0.7 mm was trapped inside a light brown diamond. Photomicrograph by Kyaw Soe Moe; field of view 1.58 mm.
The iridescent crystal inclusion in the 1.07 ct light brown type IIa diamond in the figure above was identified by Raman spectroscopy as ferropericlase. Ferropericlase, (Mg,Fe)O, can originate from either shallow (lithospheric) or deep (sublithospheric) depths within the earth. A stress halo was developed around the crystal by temperature and pressure changes during the ascent to the earth’s surface. The colorful iridescence may have been caused by light interference at a thin film trapped between the inclusion and the host diamond. It is rare to see ferropericlase as an inclusion in diamond, especially such a large crystal. @topic:10


Publish Year: 2023 Title: Natural Diamond with Unusual Phosphorescence Abstract: These deep-UV (<225 nm) phosphorescence images of the table (left) and pavilion (right) in a 0.90 ct D-color natural diamond with very low boron showed localized areas of the 500 nm (greenish blue) and 660 nm (red) bands. Images by Evelina Goldort.
Phosphorescence spectroscopy shows that natural type IIb diamonds can have two broad phosphorescence bands: one centered at 500 nm that appears greenish blue and one centered at 660 nm that appears red. Generally, one of these phosphorescence bands is dominant. In the Hope diamond, for example, the phosphorescence initially appears orangy red and transitions to red as the subordinate greenish blue phosphorescence fades away (S. Eaton-Magaña et al., “Using phosphorescence as a fingerprint for the Hope and other blue diamonds,” Geology, Vol. 36, No. 1, 2008, pp. 83–86). Occasionally, the faster-decaying greenish blue phosphorescence band will transition to the slower-decaying red band (Spring 2007 Lab Notes, pp. 47–48).
Recently, a 0.90 ct diamond with D color and I1 clarity was submitted to GIA’s laboratory in Ramat Gan, Israel, for a diamond dossier report. Infrared (IR) absorption spectroscopy indicated that the natural diamond was nominally type IIa. However, photoluminescence (PL) spectroscopy revealed that the diamond contained boron-related features, including the 648.2 nm peak attributed to a boron interstitial (B. Green, “Optical and magnetic resonance studies of point defects in single crystal diamond,” PhD thesis, University of Warwick, 2013), along with the observed phosphorescence. These features indicated that the diamond did contain boron, but below the detection level of IR absorption spectroscopy. The distinctive aspect was that both the red and greenish blue phosphorescence were localized and visible within the same image (see above).
The phosphorescence is attributed to donor-acceptor pair recombination. For the 500 nm band, this recombination has been identified as interactions between boron acceptors and isolated nitrogen donors (J. Zhao, “Fluorescence, phosphorescence, thermoluminescence and charge transfer in synthetic diamond,” PhD thesis, University of Warwick, 2022), while the 660 nm band is attributed to boron acceptors and unknown donors that are likely related to plastic deformation (S. Eaton-Magaña and R. Lu, “Phosphorescence in type IIb diamonds,” Diamond and Related Materials, Vol. 20, No. 7, 2011, pp. 983–989). PL maps were collected on the table and pavilion with 455, 532, and 785 nm excitation; only an undefined PL feature at 813 nm showed an apparent increase on the pavilion within the red-phosphorescing region (see above, right).
Type IIb diamonds grown by high-pressure, high-temperature (HPHT) methods almost always show the 500 nm phosphorescence and occasionally a separate orange phosphorescence band centered at 580 nm. In a few instances, HPHT-grown diamonds have shown the 500 and 580 nm bands simultaneously in different portions of the diamond (Eaton-Magaña and Lu, 2011; Spring 2023 Gem News International, pp. 155–156).
This is the first time the authors have seen spatially distinct observations of red and greenish blue phosphorescence in a natural diamond, an unusual find. @topic:4


Publish Year: 2016 Title: Ferropericlase Inclusion in Diamond Abstract: The changing iridescent colors of a ferropericlase inclusion are revealed through different facets of the host diamond. Photomicrographs by Evan M. Smith; field of view 1.99 mm.

	Most diamonds originate from the cratonic lithosphere, the basal portion of the thickest, oldest parts of continents. Rarely, diamonds are found with mineral inclusions that indicate a deeper origin, below the lithosphere, within the convecting mantle. Ferropericlase, (Mg,Fe)O, is one of the most common of such “superdeep” inclusion phases (T. Stachel et al., “Inclusions in sublithospheric diamonds: Glimpses of deep Earth,” Elements, Vol. 1, 2005, pp. 73–78). It often exhibits a vivid iridescence that serves as a helpful identifier. A 1.54 ct Fancy Light pink type IIa diamond with a spectacular ferropericlase inclusion was recently examined in GIA’s New York lab (see above). The exact cause of this iridescence is unknown, but it may arise at the inclusion-diamond interface due to thin-film interference from trapped fluid or structural coloration from ultra-fine exsolution of magnesioferrite. The iridescent colors of these ferropericlase inclusions change with viewing and lighting angles. The iridescence is not always uniform and can sometimes be absent, in which case the inclusion appears a transparent deep brown color.

	Strictly speaking, ferropericlase inclusions alone do not necessarily indicate a sublithospheric origin (T. Stachel et al., 2005). This is the case for the present diamond, so the assignment of sublithospheric origin is only tentative. It may be possible to create ferropericlase at shallower depths, in the lithosphere, if special conditions occur that lower the availability of silica. @topic:10


Publish Year: 2023 Title: Rainbow Mountain in Natural Diamond Abstract: These iridescence features observed in a 1.71 ct natural diamond (top) were reminiscent of Rainbow Mountain in Peru (bottom). Photomicrograph by Tejas Jhaveri; field of view 2.90 mm. Bottom photo courtesy of Daniel Sánchez Ibarra (Wikimedia Commons).
At GIA, we occasionally see diamonds with inclusions that resemble natural objects. A breathtaking example was recently observed in a 1.71 ct, H-color, I2-clarity natural diamond. The deep feather in the figure above (top) shows an iridescence feature resembling Montaña Arcoíris (Rainbow Mountain) in the Andes Mountains of Peru (see above, bottom). Thirty years ago, a diamond with a similar feature (Summer 1993 Lab Notes, pp. 123–124) was described as having iridescence due to a thin-film separation caused by a “V”-shaped dislocation.
As with the previously described diamond, the iridescence in this diamond is only visible at some orientations. This memorable effect showcases the beauty of the natural world within the diamond. @topic:10


Publish Year: 2023 Title: An Iridescent “Insect Wing” in Diamond Abstract: A subsurface feather in diamond resembling an insect wing, with visible iridescence caused by thin-film interference. Photomicrograph by Matthew Hardman; field of view 2.90 mm.
Diamond is very resistant to scratching and is often referred to as the hardest mineral on Earth due to its compact crystal structure. However, diamond is not indestructible, and it can be fractured or even broken apart during ascent from the mantle to the earth’s surface through fast, violent kimberlite eruption. Collision with rocks in high-energy rivers also results in percussion marks on the surface of alluvial diamonds (e.g., J.W. Harris et al., “Morphology of monocrystalline diamond and its inclusions,” Reviews in Mineralogy and Geochemistry, Vol. 88, No. 1, 2022, pp. 119–166). Surface cracks extending into the interior of a diamond are referred to as “feathers” in the gem trade, and these often have a negative effect on the clarity grade.
Fractures within diamond can cause fascinating optical phenomena on rare occasion. The authors recently examined a 0.39 ct Fancy Deep brownish yellowish orange type Ib/IaA diamond containing multiple feathers and graded as I2 clarity. These natural features had not been filled with a clarity-enhancing material. The largest feather located on the table facet of the diamond resembled an iridescent insect wing (see above).
Iridescence is an optical phenomenon caused by interference of light, typically seen in gemstones with cleavage or repeating submicroscopic structures (e.g., X. Lin and P.J. Heaney, “Causes of iridescence in natural quartz,” Spring 2017 G&G, pp. 68–81). In this diamond, the feather’s iridescence was due to thin-film interference caused by a thin film of air with a thickness similar to the wavelength range of visible light. As diamond and air have very different refractive indices, there is a phase difference between the incident light reflected from the upper and lower boundaries of the thin film, resulting in constructive and destructive interference. When viewed using a broadband light source (light consisting of a wide range of wavelengths), constructive or destructive interference intensifies or attenuates certain wavelengths (colors), respectively, producing a rainbow-like interference pattern. @topic:10


Publish Year: 2023 Title: CVD Diamonds with Invisible Markings Abstract: Left: The DiamondView image of the 1.93 ct CVD laboratory-grown diamond shows numbers on the table facet. Right: The 0.60 ct CVD laboratory-grown diamond shows a logo mark on the star facet. Images by Jemini Sawant.
Laser inscription is a common practice that helps to easily identify a diamond. The inscriptions are so small as to be nearly impossible to read without magnification, but they can be easily read with a loupe or microscope to help match the diamond to a laboratory report. Laser inscription can be done on the girdle, on the center of the table, on a star facet, or under the table surface. Inscriptions under the table surface are very effective from a security standpoint, as they require significant weight loss to remove.
Recently, GIA labs in India tested two diamonds (1.93 and 0.60 ct) with interesting markings. No intentional markings were observed on these samples without magnification, nor could any be seen under a microscope. But when the diamonds were exposed to the deep ultraviolet light of the DiamondView, markings appeared (see above). Both samples were CVD laboratory-grown diamonds and treated with high pressure and high temperature after growth. The invisible markings are thought to be caused by slightly different concentrations of defects, but we do not know how they were created.
The invisible markings in these two diamonds suggest the possible introduction of a new security measure in diamonds, similar to the anti-counterfeiting measure used with passports and banknotes upon exposure to a special light. @topic:4


Publish Year: 2023 Title: Yellow Zoning in Pink Diamonds Abstract: Fancy brownish pink pear and rectangular diamonds, each weighing 0.25 ct, shown in diffused light (A and C) and in long-wave UV light (B and D). Photos by Shiva Sohrabi.
Recently GIA’s Carlsbad laboratory received a few unusual natural, nitrogen-rich type IaA pink diamonds for color origin and identification service. The pink color of these diamonds is caused by the 550 nm visible absorption band, with the color concentrated within parallel narrow bands known as pink graining (S. Eaton-Magaña et al., “Natural-color pink, purple, red and brown diamonds: Band of many colors,” Winter 2018 G&G, pp. 352–377). In diffused light, they displayed faint yellow color zoning (see above, A and C). Further inspection under long-wave UV revealed strong yellow fluorescence confined to areas with yellow color zoning (see above, B and D).
Photoluminescence (PL) spectra (excited by 514 nm laser) collected from the area with yellow zoning show a broad band centered at ~710 nm. This broad emission band and corresponding strong yellow fluorescence are typically observed in yellow or orange diamonds colored by the 480 nm visible absorption band (C.M. Breeding et al., “Naturally colored yellow and orange gem diamonds: The nitrogen factor,” Summer 2020 G&G, pp. 194–219). These gemological and spectroscopic features suggest that separate color centers produce pink and yellow colors within these diamonds, though the 480 nm visible absorption band cannot be detected with ultraviolet/visible/near-infrared (UV-Vis-NIR) spectroscopy (possibly due to the fact that the yellow color zone is volumetrically small compared to the rest of the diamond, and that the UV-Vis-NIR absorption spectroscopy is a bulk analysis technique).
The mechanism of the formation of these unusual pink diamonds has not been determined and to the authors’ knowledge, such diamonds showing localized regions colored by the 550 nm band and 480 nm band have not yet been documented. Since we know very little about the physics of the 480 and 550 nm visible absorption bands, their co-occurrence within single diamonds might help us to better understand the structures of defects that are related to these features. By paying careful attention to the details of color and fluorescence zoning, more of these unusual rare pink diamonds may be identified. @topic:4


Publish Year: 2013 Title: Buff-Top Round Diamond Abstract: Figure 1. A profile view of this buff-top round diamond shows its low polished dome. Photo by Jian Xin (Jae) Liao.

              The modern round brilliant diamond is getting a “new old” look with the use of Japanese laser technology. Diamond’s high refractive index and adamantine luster make it ideal for faceting to produce dramatic scintillation, brilliance, and fire. One of the oldest and simplest cuts is the cabochon, with its smooth convex dome. A popular cut among colored stones, the cabochon is rarely if ever used in diamonds due to the gem’s extreme hardness and the difficulty in polishing it into a smooth, rounded surface. The New York lab recently examined several diamonds with an interesting variation on the cabochon.

About 30 buff-top round diamonds ranging from 0.25 to 1.50 ct, originally submitted to GIA’s Japanese lab, were received for grading. The buff-top cut has a low cabochon dome with a faceted pavilion (figure 1). These diamonds were cut with four short main pavilion facets (figure 2). This rare cut posed a challenge for the grading staff, as the smooth dome and faceted pavilion combined to produce internal reflections that made it very difficult to see clearly into the stone. Although diamonds can be cut with lasers, the polishing process with the use of diamond abrasives into a smooth rounded surface is both laborious and time consuming. The unfaceted dome was likely created using the same technology that produced the first synthetic nano-polycrystalline diamond sphere in Japan in 2011. One Japanese study (T. Okuchi et al., “Micromachining and surface processing of the super-hard nano-polycrystalline diamond by three types of pulsed lasers,” Applied Physics A: Materials Science & Processing, Vol. 96, No. 4, 2009, pp. 833–842) found that pulsed lasers most efficiently produce a smooth, undamaged surface for fine finishing diamonds. A combination of three lasers was used: a near-infrared laser for the rough shaping, and ultraviolet and femtosecond lasers for fine finishing (E. Skalwold, “Nano-polycrystalline diamond sphere: A gemologist’s perspective,” Summer 2012 G&G, pp. 128–131).

	Figure 2. Viewed face-up, the buff-top diamond shows an arrangement of four main pavilion facets. Photo by Jian Xin (Jae) Liao.
This advancement in diamond finishing offers new possibilities for a variety of interesting shapes and forms that could not be achieved with previous methods of polishing and faceting alone. Diamond cabochons, completely smooth spherical beads, and sugarloaf cuts could emerge next. @topic:4


Publish Year: 2020 Title: Graphitic Cavities on Diamond Abstract: The laser cavities on the star facet (left) and in reflected light (right). Photomicrographs by Troy Ardon; field of view 1.5 mm.
An atypical series of graphitized cavities was recently observed on a star facet (see above, left) of a 0.45 ct near-colorless round brilliant diamond. The presence of graphite was confirmed with Raman spectroscopy. The observed residue surrounding the craters could have been the result of a lasering process.
Laser sawing is now the standard way to shape rough into blocked shapes for brillianteering and polishing, and laser drilling is used to treat internal inclusions. The laser marks were not the typical oscillating lines of manufacturing remnants. These remnants on extra facets or natural surfaces are usually left behind for a variety of reasons such as saving weight. Neither was there an associated internal inclusion, which one would expect if this were a treatment, though a shallow inclusion could have been completely removed by this lasering. The only other internal inclusion was a dark brown crystal on the opposite side of the table, which had not been treated by lasering.
Reflected light (see above, right) revealed a small “island” of the original facet left behind, evidence that many craters in close proximity joined together to form one larger cavity. This is also the reason it is suspected that this cavity system was caused by a laser as opposed to another thermal process, such as a jeweler’s torch. Something like a torch is unlikely to have left an intact section of the facet in the center of a burnt-out cavity. The fact that there were many connected craters does make these cavities seem intentional, though the purpose is not obvious. @topic:4


Publish Year: 2015 Title: Cleavage System in Pink Diamond Abstract: Figure 1. This Fancy Intense purplish pink 0.29 ct diamond was host to a complex cleavage network. Photo by Robison McMurtry.

	A 0.29 ct natural Fancy Intense purplish pink diamond with a microscopically interesting geometric feature (figure 1) was recently examined at GIA’s Carlsbad laboratory. A network of planar cracks, oriented in three octahedral directions, was observed at the surface of a pavilion facet (figure 2). These linear cleavage cracks were caused by localized strain on an octahedral plane.

Figure 2. Three directions of cleavage along octahedral planes are seen in this pink diamond. Photomicrograph by Jonathan Muyal; field of view 1.22 mm.

	The octahedral plane in diamond has the weakest atomic bonding, which means that when a diamond is strained, this is the direction that will be most affected. This stone offers the perfect example of strain products in pink diamond. The purplish pink color results from plastic deformation along octahedral planes. Also present along the octahedral plane is a zone where the strain was so great that it was relieved by cracking, creating the cleavage network seen in figures 2 and 3.

Figure 3. Between crossed polars the diamond shows high-order interference colors consistent with the strain causing the cleavage network along the octahedral planes. Photomicrograph by Jonathan Muyal; field of view 0.62 mm.

	The cleavage network in this diamond is the most aesthetic one encountered by the author to date due to its finely textured geometric pattern. Interestingly, the clue to the planar cleavage network lies in the bodycolor of the stone, which indicates significant strain. This high-order strain is easily revealed between crossed polars. If a cleavage network is present in a diamond such as this, it may have a strain-induced bodycolor as well. @topic:4


Publish Year: 2023 Title: Xenomorphic Garnet in Diamond Abstract: A purplish pink xenomorphic octahedral garnet crystal seen in a diamond. Note the trigons on the upper right octahedral face and stress fractures around the intersections of the crystal faces. Photomicrograph by Britni LeCroy; field of view 1.26 mm.
Garnet is a nesosilicate mineral belonging to the cubic crystal system. The crystal habit most commonly assumed by this mineral is a dodecahedron. A garnet crystal with rare octahedral morphology was recently encountered in the form of a xenomorphic inclusion within diamond. Xenomorphism is the process by which a growing mineral forces a syngenetic mineral inclusion to adopt a crystal habit familiar to the host (J.I. Koivula, The MicroWorld of Diamonds, Gemworld International, Northbrook, Illinois, 2000). Xenomorphic crystals may also be referred to as “anhedral” since they lack their own characteristic crystal shape in favor of the host’s. However, it should be noted that not all anhedral included mineral crystals are xenomorphic. As an octahedron is the most common diamond habit, the garnet inclusion grew into this form, complete with triangular growth marks visible on one of the octahedral faces (see above). Xenomorphism in diamond can also occur with mineral inclusions that do not belong to the cubic crystal system, and these can be forced into other diamond habits. For example, a monoclinic crystal of diopside may be forced into a cuboctahedral habit. Xenomorphic crystals are just one of many unique inclusion types possible within diamond. @topic:10


Publish Year: 2023 Title: Starry Night in Diamond Abstract: Figure 1. Rare cloud inclusions were observed in a 0.53 ct D-color diamond. Photomicrograph by Nathan Renfro; field of view 2.39 mm.
In astronomy, a star cloud is defined as a group of many stars. A diamond recently submitted to GIA’s Surat lab contained cloud inclusions resembling a starry night (figure 1). This diamond was a 0.53 ct D-color natural round brilliant with SI2 clarity. Fourier-transform infrared absorption spectroscopy indicated a type IaAB diamond with low nitrogen content of about 5 ppm. Each of the cloud inclusions had apparently randomly placed dendrites. The star field in this stone appeared comparable to a diamond described previously (Fall 2017 G&G Micro-World, p. 369); however, the individual clouds in that diamond resembled crosses of uniform orientation that corresponded with the cube face.

Figure 2. This deep ultraviolet fluorescence DiamondView image shows that the cloud inclusion features appear to be contained within a single growth zone. Image by Sally Eaton-Magaña.
Photoluminescence (PL) mapping using 455, 532, and 633 nm excitations was used to determine whether optical features could be detected within the cloud inclusions, as that analysis method has proven useful with cloud features in other diamonds (Fall 2020 Lab Notes, pp. 416–419). However, the PL maps were inconclusive, as no distinctive features were detected within the star-shaped inclusions. In deep ultraviolet fluorescence imaging, they appeared to be contained within the same growth zone (figure 2).
The inclusion suite was an interesting collection of cloud formations and a delightful discovery in this unusual diamond. @topic:4


Publish Year: 2023 Title: A “Flying Insect” in Diamond Abstract: This partially exposed orange garnet inclusion with surrounding fractures in a brownish yellow diamond resembled a flying insect. Photomicrograph by Mei Yan Lai; field of view 1.58 mm.
The authors recently examined a 0.75 ct type IaA Fancy Light brownish yellow diamond. This diamond, with a clarity grade of I1, contained at least 10 orange inclusions, the largest one ~500 μm in its longest dimension. A partially exposed orange inclusion resembled a flying insect, with “flapping wings” and “antennae” caused by fractures around the inclusion (see above). Raman spectroscopy revealed the inclusion to be pyrope-almandine-grossular garnet, (Mg,Fe,Ca)3Al2(SiO4)3, a major constituent mineral of eclogite.
Eclogite and peridotite are the major diamond host rocks in the lithospheric mantle. Worldwide, the ratio of diamonds with eclogitic mineral inclusions to those with peridotitic inclusions is ~1:2 (T. Stachel and J.W. Harris, “The origin of cratonic diamonds – constraints from mineral inclusions,” Ore Geology Reviews, Vol. 34, No. 1-2, 2008, pp. 5–32).
Although the presence of inclusions generally reduces a diamond’s clarity grade, diamonds containing visually identifiable mineral inclusions are uncommon. Studies of some smaller diamonds (~2 mm) from South Africa and Botswana revealed a low abundance of inclusion-bearing diamonds (about 1% in a total of one million diamonds examined; Stachel and Harris, 2008). For a gem-quality diamond to contain more than 10 mineral inclusions is therefore notable. @topic:10