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

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

Explore the world of diamonds and colored gemstones.

Objectivity and independence are the hallmarks of all GIA reports and services, and GIA has elaborate processes in place to ensure a diamond’s anonymity through the grading process. Upon arrival to ...

GIA Natural Diamond Reports offer thorough, unbiased analysis in an easy-to-understand format.

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Emerald is 7.5 to 8 on the Mohs scale and has fair to good toughness, making it a stone that requires more care in wearing than ruby or sapphire. Even so, emeralds are beautiful stones for all types ...

Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive.

Because of its basal cleavage, topaz requires special care during cutting, polishing, and mounting. It’s not very tough, so a hard blow might split it, and extreme pressure or sharp temperature ...

Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive.

Common substances like sand and dust are composed mostly of quartz, the mineral species that includes the variety citrine. So, while citrine is a great gemstone for use in jewelry, it should be ...

Turquoise is one of the world’s most ancient gems. Archaeological excavations revealed that the rulers of ancient Egypt adorned themselves with turquoise jewelry, and Chinese artisans were carving it ...