As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.

Sapphire comes in a variety of colors. This rare 1,126.00-ct. corundum crystal’s pinkish orange color is called padparadscha, named after the lotus flower. - © GIA ...

Due to the overwhelming popularity of GIA’s limited time, no-charge offer, all GIA Essentials classes starting in May and June – the period of the offer – are full. The offer is closed and we cannot ...

这颗大型澳大利亚淡色凸圆面蛋白石，重达 117.85 克拉。蛋白石上面布满了橙色和绿色的星火图案小型游彩闪光，灰色的体色缀以柔和的蓝色斑点。 每一颗蛋白石的外观和质量都大有不同。正如雪花和指纹一样，每颗宝石都有明显的差异。 蛋白石评估应在可控 ...

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 ...

Those born in January are lucky to have the beautiful and diverse garnet as their birthstone. Garnets are commonly red but also come in an extraordinary range of beautiful colors, including orange, ...

To address concerns about laboratory-grown and treated diamonds being mixed into parcels of melee, GIA has developed an automated system to analyze and sort melee-size diamonds quickly and accurately.

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

Reviews the advancements and major trends in laboratory-grown diamonds observed by GIA since 2007. Gemological and Trace Element Characteristics of Cassiterite from Yunling, China Examines gem-quality ...

The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet. Twenty such diamonds were studied to investigate the relationships ...

Attain your dreams of a GIA education with scholarships. We encourage on-campus students to apply for assistance and we are happy to help you coordinate your efforts. GIA-administered scholarships are ...

An aquamarine crystal in its natural state shows why these specimens are prized for their beauty. - Courtesy Daniel Trinchillo, Fine Minerals International Aquamarine is the green-blue to blue variety ...