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 ...

Metrology, the science of measurement and its application, plays a critical role in the accuracy of GIA’s research and laboratory services. The metrology team closely monitors the performance of ...

With decades of expertise and laboratory locations worldwide, GIA uses more advanced instrumentation that extends far beyond the boundaries of standard gemological testing. The comprehensive analysis ...

CARLSBAD, Calif. – January 29, 2025 – GIA field gemologists recently completed their one-hundredth expedition, adding to the Institute’s unrivaled store of independently verified gemological ...

Secure your spot for the Sept. 7-10 event in Carlsbad, CA CARLSBAD, Calif. – January 27, 2025 – Registration for Converge, the singular gem and jewelry event combining the unique expertise of the ...

Diamond “type” is a concept that is frequently mentioned in the gemological literature, but its relevance to the practicing gemologist is rarely discussed. Diamonds are broadly divided into two types ...

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. In describing colored gemstones, the major ...

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.

Cubic zirconia can be produced in large sizes and in different colors. These colorless and pinkish purple CZ are, from left to right, 44.49 carats, 29.86 carats and 54.60 carats. Photo: Tino Hammid.

Diamonds, colored stones, and pearls submitted to GIA laboratories today will have services completed and be ready for return by the estimated dates noted below. Requesting additional services after ...

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 ...

The beautiful shimmer of light that's characteristic of moonstone is apparent even in its rough form. This special property is maximized by a quality cut. - David Humphrey Moonstone’s delicate beauty ...