The American Gem Society (AGS) is a trade association of retail jewelers, independent appraisers, suppliers, and selective industry members, which was founded in 1934 by Robert M. Shipley.
The Society is based in Las Vegas, Nevada, along with the affiliated American Gem Society Laboratories (AGSL) (founded in 1996) and the American Gem Society Advanced Instruments Division (founded in 2004).
The Society trains and certifies jewelers, gemologists, and jewelry appraisers. Diamond grading is a specialty of the American Gem Society Laboratories and the Society has developed its own cut, color, and clarity standards.