News & Articles

552.7 ct Yellow Diamond from the Diavik Mine
The Largest Diamond Ever Discovered in North America

GIA examines a 552.7 ct diamond from the Diavik mine in Canada.

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Rough tsavorite.
Revealing “The Angel in the Stone”: The Largest Known Square Cushion-Cut Tsavorite

At the AGTA show, Bridges Tsavorite unveiled the largest known square cushion-cut tsavorite, weighing 116.76 ct.

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Natural diamond with CVD synthetic diamond overgrowth
CVD Layer Grown on Natural Diamond

A composite of synthetically grown and natural diamond was recently identified by the Carlsbad laboratory.

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Spring 2019 G&G: Tourmaline Classification, Provenance of Freshwater Pearls, and the Annual Tucson Report

A summary of the Spring 2019 issue of Gems & Gemology.

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Observations on the Heat Treatment of Basalt-Related Blue Sapphires

Researchers from GIA’s Bangkok laboratory seek to identify low-temperature heat treatment in basalt-related blue sapphires.

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Rough diamond, yellow in color
Diamond Research Gives Clues to the Formation of the Continents

Mineral inclusions reveal continents’ construction – and help researchers date diamonds.

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