A non-profit professional organization of jewelers funded by Robert Shipley in 1934.
See Alexandrite Tsarstone collectors guide, Definition of American Gem Society, http://w.alexandrite.com/viewpage.html?id=GG-086-00011 (A non-profit professional organization of jewelers funded by Robert Shipley in 1934.) (as of May. 31, 2026, 16:25 GMT).