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, ...

Yes. GIA has been grading laboratory-grown diamonds since 2007. Beginning July 1, 2019, GIA Laboratory-Grown Diamond Reports and identification reports no longer use the term “synthetic.” The GIA ...

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

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 ...

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, ...

A new type of African chalcedony with the trade name “Aquaprase” shows unique composition and attractive color.

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 ...

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 ...

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

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 ...

Stability Alexandrite is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Cleaning Warm, soapy water is always safe for cleaning ...