Separation of Natural from Laboratory-Grown Diamond Using Time-Gated Luminescence Imaging

Researchers from De Beers Group Technology present a technique that expands on the surface luminescence used in the DiamondView instrument to provide additional imaging information and quickly distinguish colorless or near-colorless natural diamond from laboratory-grown diamond.

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The “Fragility of the Eternal” Kunzite: Origin, Cutting, and Identification

A master gem carver bases his latest design off a stunning stained glass window when attempting the world’s largest known cut kunzite.

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Purplish Pink Diaspore Reportedly from Afghanistan

Diaspore, an orthorhombic aluminum oxide hydroxide mineral with the formula AlO(OH), is a relative newcomer to the jewelry scene, with some stones possessing a captivating ability to change color between pale green, yellow, pink, and purple when viewed in different sources of light.

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Finders, Keepers: Field Trip to Crater of Diamonds, USA

There’s only one place on earth where the general public can prospect for diamonds directly from a primary kimberlite pipe: Crater of Diamonds State Park.

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Fossil Ivory Update with Lee Downey

Lee Downey, owner of Artifactual (Tucson, Arizona), spoke with us in early 2020 about his 35 years in the fossil ivory carving trade and the impact of ivory bans on his business.

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History of the Chivor Emerald Mine, Part II (1924–1970): Between Insolvency and Viability

Many legends are told about the history of the Chivor emerald mine.

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Quench-Crackled Dyed Blue Chalcedony Resembling Larimar

Raman spectroscopy confirms sea-blue beads with a similar appearance to Larimar are actually quench-crackled chalcedony.

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Marble Imitation of Jadeite Rough

In recent decades, jadeite prices have risen dramatically. Driven by profit, a variety of imitations are found in the jadeite jewelry market.

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ジュエリーのファンシー メレーが天然ダイヤモンドかどうか、どうすれば分かりますか?

非開示のラボラトリー グロウンおよび類似石のファンシー メレーが天然ファンシー メレーに混在していることに対する業界の懸念にGIAがどのように対処しているかについて学びましょう。

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歴史的書籍リスト:ギリシャ、ラウリウムの古代の銀山

ギリシャのラウリウムにある古代の銀山に関して編集された注釈付きの書籍リスト

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GIAナレッジ セッション:宝石学の情報を分かち合う新しい方法

Webinars are an easy, informal way for GIA experts to share information and stay connected to the community of researchers and gem and jewelry lovers.

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歴史的書籍リスト:ブラジル産のダイヤモンドおよびカーボナード(第2部)

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歴史的書籍リスト:ブラジル産のダイヤモンドおよびカーボナード(第1部)

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写真に秘められた逸話:巨大なアクアマリンと「華麗な」自然

宝石学フォトジャーナリストのRobert Weldonが、お気に入りの写真に秘められた逸話を紹介します。

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Solid Carved Dark Gray Diamond Ring

A ring made entirely of natural diamond was recently submitted to GIA’s New York laboratory.

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Ethical Gem Fair

A transparent supply chain and the education of artisanal miners were two of the many topics discussed at Tucson’s first Ethical Gem Fair.

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Diamonds Are Not Forever! Diamond Dissolution

Violent kimberlite eruptions impact the surface features of diamonds, which can give scientists useful information about how diamonds react with the fluids in the mantle.

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Sunstone Plagioclase Feldspar from Ethiopia

Advanced analytic techniques are critical for separating Ethiopian feldspar from Oregonian and copper-bearing feldspar with undetermined color origin.

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Burmese Star Peridot

A rare Burmese star peridot cabochon is characterized by a soft four-rayed asterism and extremely fine acicular inclusions.

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A Quantitative Description of the Causes of Color in Corundum

Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.

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