The American Gem Society (AGS) ?
Found in 1934 by GIA founder Robert M. Shipley, the AGS is a trade association of retail jewellers, independent appraisers, suppliers, and selective industry members. Members are held to a high code of ethics with emphasis on consumer protection and education.
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 jewellers, gemmologists, and jewellery appraisers. Diamond grading is the specialty of the American Gem Society Laboratories and the Society has developed its own cut, colour, and clarity standards.
TYPES OF CERTIFICATES ISSUED BY THE AGS
AGSL Diamond Quality Document
A document evaluating the colour, clarity, carat weight, and cut of a diamond, including a detailed diagram plotting the diamond’s proportions and illustrating any present inclusions.
AGSL Diamond Quality Report
A report detailing the cut, colour, clarity, and carat weight of diamonds in both AGS and GIA terminology