A look at the history of analytical instruments used for gem testing. UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ...

Cultured pearls come in different sizes, shapes, and colors. Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most ...

The discovery of significant quantities of gem-quality sapphire in Minas Gerais could add corundum to the formidable list of gem species already commercially produced in Brazil. The presence of ...

GIA is the creator of the 4Cs of diamond quality and the leading research and education center for gems and gemology. Considered the world authority on gems, the Institute is open to the public Monday ...

三月的两种生日石海蓝宝石和血石在外观上有着很大的差异，但在庇佑人们幸福安康这方面，二者都享有盛誉。海蓝宝石生日石让人想起大海的颜色。从深绿-蓝到淡弱绿蓝色的色彩，刻面海蓝 ...

すべてのGIA拠点でご利用可能。 GIA ダイヤモンド オリジン レポート: 科学に基づくトレーサビリティ 消費者は、これまで以上に持続可能かつ倫理的に調達された製品に対する意識を高めてい ...

GIA studied more than 400 important gemstones from the Gübelin Collection and is committed to sharing this repository of gemological information. This work is a valuable resource for all students, ...

However gem quality diamonds are fashioned from the original crystal shape they possess a combination of brightness, sparkle, fire, and sense of purity not matched by other gems. - Jeff Scovil, ...

This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...

The green turquoise cabochon, from an American mine, might become part of a designer’s unique jewelry piece. The even blue color of the cabochon on the right would be called “Persian blue” in the ...

Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA.

The 75.47-carat Hooker Emerald was worn by Ottoman Sultan Abdul Hamid II, the last sultan of the Ottoman Empire. Photo by Chip Clark, courtesy Smithsonian Institution, National Museum of Natural ...