Blue diffusion-treated sapphires are becoming more prevalent than ever before. The diffusion technique, which involves the addition of color-causing chemicals during heat treatment, results in a thin ...

Every GIA diamond grading report contains an assessment of a diamond’s polish and symmetry, which are contributing factors in determining the overall quality of a diamond’s finish. In evaluating ...

A 43-carat alexandrite in the collection of the British Museum. Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine ...

Birthstones are a fun, popular and colorful introduction to the world of gemstones. They appeal to audiences around the world regardless of gender, age, nationality or religion. Birthstones carry ...

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 ...

The Graduate Jeweler diploma program is a hands-on experience that introduces students to the knowledge and skills required for a career in jewelry fabrication and repair. You will work with gemstones ...

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 ...

Gem-quality synthetic or laboratory-grown diamonds are more available in today’s jewelry marketplace than ever before, causing both interest and concern about lab-grown diamonds and whether ...

Figure 1. The color zoning of amethyst from Boudi often displays a characteristic hourglass shape. Photo by Abdelghani El Harfi and Salahaddine Mouaddib. For 25 years, the Moroccan locality of Boudi ...

Miners collect spinels from gravel at the end of a long day at Man Sin. Photo by Vincent Pardieu, © GIA. In the spring of 2001, I was studying gemology in Yangon ...

This 17.53-carat amethyst displays a rich reddish purple color. - Lydia Dyer, Super Trillion Cut Amethyst gem courtesy of John Dyer & Co. Amethyst has been the most-prized quartz variety for centuries ...

The GIA Knowledge Sessions are a series of talks and seminars that engage participants in the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and ...