Full quality assessment, color grade and clarity plot. Identifies natural vs. treated color. For loose, natural, colored diamonds 0.15 carats or more.

The Panyu district is a leading gemstone cutting and jewelry manufacturing center for the global gem and jewelry industry. Situated near Hong Kong, it plays a key role in jewelry exports from mainland ...

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 ...

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.

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

Natural mint-green chrysoberyl, much of it extremely clean, is also found in Ilakaka, Madagascar; Sri Lanka; and Mogok, Myanmar. Prior to this study, there had been very little investigation into ...

Within a short time, 90 more claims appeared in the same 20-square-mile area. No one was quite sure what the beautiful crystals were, but everyone wanted to lay claim to the profits they were certain ...

Stability Rose quartz is generally stable when exposed to light and heat. Cleaning Warm, soapy water is always a safe method for cleaning rose quartz. Cleaning with ultrasonic and steam cleaners ...

Birthstones are a fun, popular and colorful introduction to the world of gemstones. They appeal to audiences around the world regardless of gender, age, nationality or religion. Birthstones carry ...

Toughness Any stone, including a diamond, will break if it’s hit hard enough in the right place. Toughness is a measure of how well a gem can survive an impact and resist breaking, chipping, or ...

The quarterly journal of the Gemological Institute of America.

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