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CVD, HPHT and Natural Diamonds
Article
Is There a Difference Between Natural and Laboratory-Grown Diamonds?

Learn about the differences – and similarities – between natural and laboratory-grown diamonds, and how GIA’s researchers and grading laboratories can tell the difference

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GIA field expedition team in Ethiopia
Land of Origins: A Gemological Expedition to Ethiopia

Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia.

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A heart-shaped piece of pink drusy hangs from a gold chain.
Article
Dreamy Drusy: Minute Crystals Shimmer in Dramatic Designs

Drusy jewelry has surged in popularity in recent years. Celebrities wear it on the red carpet and designers clamor for it at gem shows.

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Looking down the crystal axis of a backlit 58.83 ct trapiche emerald
Article
Emerald: The Superstar of Trapiche Gemstones

Trapiche emeralds, which display a distinct six-spoke wheel pattern, set the standard as some of the finest and most spectacular crystals unearthed.

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Inclusions in sapphire SASLR050_01.
U-Pb Ages of Zircon Inclusions in Sapphires from Ratnapura and Balangoda (Sri Lanka) and Implications for Geographic Origin

Establishes a metamorphic origin for sapphire samples from these deposits, supported by their trace-element composition and inclusion characterization, including the age dating of zircon inclusions.

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Rough blue spinel crystals from Luc Yen
Blue Spinel from the Luc Yen District of Vietnam

Offers geological context and gemological characterization of this increasingly popular vivid blue spinel from northeast Vietnam.

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Gray Corundum Coated by Black Spinel Layer
Corundum with Spinel Corona from the Tan Huong–Truc Lau Area in Northern Vietnam

Explains the reactions responsible for the formation of a well-developed reaction rim of spinel that surrounds the corundum core in some specimens from this deposit.

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Sapphires from Bingham Canyon (Utah) and Yogo Gulch
Gem Localities and Formation

Poster abstracts on “Gem Localities and Formation” from GIA’s 2018 International Gemological Symposium.

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FTIR spectrum and DiamondView images of type Ib-IaA diamond
Diamond Geology

Poster abstracts on “Diamond Geology” from GIA’s 2018 International Gemological Symposium.

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Photo Montage

Scenes from the 2018 GIA International Gemological Symposium

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