We present an algorithm for enumerating all possible faceting arrangements of dihedrally symmetric diamond cuts. We first separate the question into enumerating crowns a ...

Explore aquamarine history, research, quality factors, and more in the GIA Gem Encyclopedia.

This 6.30-carat black boulder opal from Queensland, Australia, displays vivid play-of-color. Black opals are highly valued because their dark body tone showcases play-of-color more dramatically than ...

Sally Eaton-Magaña, Christopher M. Breeding, and James E. Shigley ...

Your name or store info is removed so grading is completely unbiased. Every pearl or pearl strand, whether from a local jeweler or a globally recognized brand, is evaluated using the same rigorous, ...

Fluorescence and phosphorescence can assist in revealing whether a gemstone is natural, laboratory-grown or treated. GIA developed this guide so retailers can use fluorescence tests to help identify ...

Explore diamond history, research, quality factors, and more in the GIA Gem Encyclopedia.

An Identification Report, with geographic origin added. For polished, loose or mounted natural alexandrite, demantoid, emerald, jade, opal, Paraíba tourmaline ...

In the spring of 2001, I was studying gemology in Yangon, Myanmar, thanks to the support of U Kyaw Thaung, a Burmese merchant from Mogok. It was a great period in my early life as a gemologist, living ...

Designed for clients who seek in-depth insights into every aspect of a jewelry item. Comprehensive analysis of the diamonds in an item, including number of stones, shape, estimated carat weight, color ...

Existing methods of classifying garnets have proved to be inadequate to deal with some new types of garnets discovered recently. A new classification system based on the chemical analysis of more than ...

Starting in May, many Sri Lankan dealers have traveled to Ethiopia to buy this material, causing steep price increases in local gem markets. All of the mining around Chila is artisanal, but large ...