Accredited Gemologists Association: Amber, ruby, coral, topaz, tanzanite—the list of gemstones is long. They come in a rainbow of colors and are commonly classified as either precious or semiprecious stones. These facts are well known, we’re sure, to members of the Accredited Gemologists Association. Established in 1974, AGA counts some of the world’s leading gemstone specialists among its members.

Gemological Institute of America: Despite the variety of gems found throughout the world, diamonds are among the most popular, at least in America, which purchases more than 40 percent of the world’s gem-quality diamonds. That’s according to the Gemological Institute of America, the creator of the international diamond-grading system. Developed in the 1940s, the system classifies these precious stones based on the 4Cs: cut, color, clarity, and carat.

American Gem Trade Association: Interested in purchasing some gemstones? Check out the American Gem Trade Association’s online trading platform, GemeShare, where you can also buy jewelry already made with these stones. AGTA also sponsors the Spectrum Awards, an industry competition that honors jewelry designers who incorporate natural colored gemstones into their work.

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