Unheated and Unusual Colors
Margit Thorndal of Madagascar Imports offers her perspective on the colored stone market.
Update on the Green Dragon Demantoid Mine in Namibia
Stephan Reif explains the mine-to-market approach at the largest continuously operating demantoid deposit.
Colombian Emerald Industry: The New Generation
Luis Gabriel Angarita and Edwin Molina share their experiences and perspective on the Colombian emerald industry.
Quarterly Crystal: Cr-Diopside in Diamond
A bright green chromium diopside inclusion is seen in a diamond from South Africa's Kimberley mine.
Type IIa Diamond with Extraordinary Etch Channels
Rare dissolution etch channels are seen in a natural diamond.
Five CVD Synthetic Diamonds Greater Than Three Carats
The GIA lab examines five gem-quality CVD-grown diamonds in sizes that reflect the improving technology of the synthetic gemstone industry.
HPHT-Processed Diamond Fraudulently Represented as Untreated
An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.
Cat's-Eye Demantoid and Brown Andradite with Horsetail Inclusions
The examination of two unusual garnets results in identifications issued for the first time in GIA's colored stone report records.
Fracture-Filled Diamond with "Rainbow" Flash Effect
The material used to fill a large fracture in a diamond yields an unexpected iridescence under two different illuminations.
Natural-Color Green Diamonds: A Beautiful Conundrum
Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.
Iridescence in Metamorphic “Rainbow” Hematite
Analyzes the substructures that cause the intense iridescence observed in “rainbow” hematite from Minas Gerais, Brazil.
DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan
Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.
Update on "Low-Temperature" Heat Treatment of Mozambican Ruby: A Focus on Inclusions and FTIR Spectroscopy
Non-Bead-Cultured Pearls from Pinctada margaritifera
A new report from GIA's Bangkok laboratory examines a set of 120 NBC samples stated to be of "Tahitian" origin.
Non-Bead-Cultured Pearls from Pinctada margaritifera
A new report from GIA's Bangkok laboratory examines a set of 120 NBC samples stated to be of "Tahitian" origin.
New Developments and Opportunities for GIA Alumni Association Chapters and Members
A renewed structure, expanded education opportunities and other tools will help GIA Alumni Association chapters and members communicate GIA connection.
ジェモロジスト、巨大な結晶の世界へ興味を掻き立てることを目指す
「冒険好き」の同窓生が、巨大なセレナイトの結晶を観察・研究するために地下の洞窟に潜り込み、世界中の皆さんにその結果を報告します。
M.D. Hohenstineによる宝石の展示作品： ショーウィンドウを飾る裸石（ルース）を使った好評のアートを作成するプロセス
宝石商のM.D. Hohenstineの壮大な展示作品は、50年以上もの間、オハイオ州コロンバスのダウンタウンでこよなく愛されている伝統でした。
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