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 ...

Below is the list of recognized holidays when GIA locations will be closed.View the holiday schedule for all GIA locations worldwide.

The Robert Mouawad Campus at GIA World Headquarters in Carlsbad offers world-class gem studies with advanced classrooms, a renowned lab, and an iconic museum.

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 ...

The Jewelry Design & Technology diploma program covers topics essential to becoming a jewelry designer and CAD (computer-aided design) technician, including designing a piece of jewelry from a concept ...

Marble-hosted ruby and spinel deposits represent the foremost source of colored gems in Central and Southeast Asia (Garnier et al., 2008). They are contained in a series of platform carbonates that ...

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 ...

This 3.28-carat Paraíba tourmaline's vivid violetish blue hue rivals the finest sapphires. Because of this tourmaline's rarity, its per-carat price is also likely to rival the price of fine sapphire.

One of the most famous gems in the world, The Hope Diamond is a 45.52 carat Fancy Deep grayish blue diamond. GIA researchers examined it in 1988. Photo: Chip Clark, courtesy of Smithsonian Institution ...

While Russia is the most famous alexandrite source, this stone from Brazil shows beautiful color change from daylight (left) to incandescent light (right). - © GIA ...

All fees are charged in the currency of the location where the item is submitted for service. To view fees, chose your gemstone type and currency.

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.