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 ...

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, ...

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

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 ...

Get details on the latest research from the GIA research team, including: natural diamond geology and mining locations, causes of colors and optical features, laboratory-grown diamond research, ...

Synthetic moissanite is much closer to diamond in overall appearance and heft than any previous diamond imitation; this article reports on how to identify and characterize it.

Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.

Sapphire, the September birthstone comes in all the colors of the rainbow – except red. Learn more about the birthstone of wisdom, loyalty, and nobility and discover its history and where it can be ...

Garnet, January’s birthstone, is one of the most diverse gemstones, as it comes in an extraordinary range of colors. The garnet birthstone is mined around the world and symbolizes happiness, wealth, ...

Discusses the role of three-phase inclusions in emerald, in combination with spectroscopy and trace-element analysis, in determining geographic origin.

Colored diamonds are in the spotlight. They’re routinely breaking records at auction houses. Learn more about these gemological marvels of the rarest order.

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 ...