A non-profit professional organization of jewelers funded by Robert Shipley in 1934.
See Alexandrite Tsarstone collectors guide, Definition of American Gem Society, http://www.alexandrite.net/viewpage.html?id=GG-086-00011 (A non-profit professional organization of jewelers funded by Robert Shipley in 1934.) (as of Feb. 08, 2012, 14:32 GMT).