GIA developed this guide so retailers can use fluorescence tests to help identify gems right in their own stores.

Colored Stone Identification & Origin Report An Identification Report, with geographic origin added. For polished, loose or mounted natural alexandrite, emerald, jade, Paraíba tourmaline, red spinel, ...

Emerald is the green to greenish blue variety of beryl, a mineral species that also includes aquamarine as well as beryls in other colors.

A guide describing frequently encountered gem treatment processes, their detection, and special care tips for treated gems.

Turquoise ranks 5 to 6 on the Mohs hardness scale. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which ...

Learn about jade's durability and how to care for your jade jewelry.

Tanzanite is one of the most popular colored gemstones in the world.- Courtesy Tanzanite Foundation ™ Tanzanite is a versatile gemstone that comes in a variety of sizes and cutting styles. Although it ...

Diamonds have a long history as a premier gemstone—a natural consequence of their beauty, rarity, and superlative physical properties such as extreme hardness. Diamonds that are mined for use as ...

Feature Gems & Gemology, Fall 2014, Vol. 50, No. 3 Observations on Pearls Reportedly from the Pinnidae Family (Pen Pearls) Nicholas Sturman, Artitaya Homkrajae, Areeya Manustrong, and Nanthaporn Somsa ...

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.

For centuries, Afghanistan has been an important source for top-quality lapis. Historians believe the link between humans and lapis lazuli stretches back more than 6,500 years. The gem was treasured ...

A list of fees by service in 7 currencies.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. All new ...