Grading Gemological Labs

Gemological Institute of America (GIA)

An independent nonprofit organization, the Gemological Institute of America (GIA) is renowned for its impartial service as the world's foremost authority in gemology. The Institute's history of ground-breaking scientific research, education, and gemological laboratory services reads as a virtual chronicle of the industry's own growth and sophistication.

From 1953, when Richard T. Liddicoat created and introduced the International Diamond Grading System™ — to the position the Institute holds today as the most respected grading and identification authority in the world — GIA has combined the principles of research, education, and service to help gem and jewelry professionals around the globe use science and product knowledge to sustain the public's trust.

The GIA can be reached at:

Gemological Institute of America (GIA)
World Headquarters
The Robert Mouawad Campus
5345 Armada Drive
Carlsbad, California 92008
Telephone: (800) 421-7250 or (760) 603-4000

American Gem Society Laboratories (AGSL)

Members of the American Gem Society, and a select group of investors established the American Gem Society Laboratories (AGSL) in 1996. Following in the footsteps of the American Gem Society, their vision was to set a new standard of excellence in the diamond grading industry, with a mission to protect the consumer through an unbiased, credible analysis of the quality factors of a diamond.

The AGSL promotes the highest professional standards of ethics, education and service. Consumers benefit from AGSL documents because they are empowered with detailed information about their diamond, and can rest assured that the report is the industry's most thorough and consistent.

The organizations can be reached at:

American Gem Society Laboratories (AGSL) Telephone: (702) 233-6120 Website:

American Gem Society (AGS) 8881 West Sahara Avenue Las Vegas, Nevada 89117 Telephone: (702) 255-6500 Website:

The American Gem Society is a not-for-profit trade association founded 70 years ago in 1934 by Robert M. Shipley. The AGS mission is "dedicated to proven ethics, gemological knowledge, and consumer protection." AGS membership includes nearly 1300 retail firms in North America representing 1400 stores, and 250 wholesale suppliers and sustaining firms.

Each AGS member firm must meet strict criteria to obtain membership including: a minimum of 2 years in business, dealing in the retail or wholesale trade (not both), and having at least one staff member with gemological training. In addition AGS member firms are committed to truth in advertising and pricing, therefore accurately representing all products and services to their customers.

Every AGS member firm must have an AGS titleholder, one who has taken the "AGS Way Course" covering a variety of topics including the AGS Diamond Grading Standards. Every American Gem Society titleholder must pass an annual recertification exam to maintain his or her membership. Any issue concerning an AGS member firm is resolved through a grievance and review process, again ensuring consumer protection, promoting confidence and trust.