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The Gemological Institute of America is an endowed, non-profit organization which provides training and other services to jewelers and other gem enthusiasts. It is one of two major organizations (the other being the American Gem Society, or the AGS) which research and define the industry's processes of grading, cutting, and identifying gemstones.

Robert M. Shipley, a Wichita jeweler, founded the GIA in 1931 in Los Angeles. He had visited Europe and came to greatly admire the guilds which helped the jewelry industries their improve their education and business ethic standards. With visions of educated jewelers dancing through his head, he returned to the US and begat the GIA.

When Shipley retired in 1952, Richard Liddicoat was appointed Executive Director (or President, as it was later called) of the organization. Liddicoat had begun his career with the GIA in 1940, served as President of the organization until 1983, when a heart attack temporarily suspended his service to the organization. He returned as Chairman of the Board later that year, where he currently serves. Liddicoat has authored and coauthored many books, most famously the Handbook of Gem Identification, which was originally authored in 1947 and is currently in its 11th edition.

The GIA has two wholly-owned subsidiaries which, because they both compete with other tax-paying organizations, pay taxes.
  • The Gem Instruments Corporation manufactures many identification and grading instruments which are used the world over:
    • Gemolite - a series of microscopes
    • Illuminator Polariscope - tests a stone's optical properties: pleochroism, whether it's singly or doubly refractive, etc.
    • Duplex Refractometer - measures the index of refraction of a stone - useful in identifying stones.
    • Diamondlite - simulates daylight to facilitate stone grading.
    • Spectroscope Unit - aids in gem identification and grading by study of the stone's spectrum.
    • GemSet - master set of color comparators which will set you back a cool $949.
  • GIA Gem Trade Laboratory, Inc., founded in 1949, specializes in developing identification methods for new gem substitutes. It services clients such as:
One of GIA's most famous accomplishments is their development of a grading and certification system for gemstones, especially diamonds. This system was first introduced by Liddicoat in 1953. The first certificate for a diamond was issued in 1957; for a colored stone, 1962.

In the case of diamonds weighing less than one carat, the report is called the GIA Diamond Dossier Grading Report. The Dossier looks like a small pamphlet which folds in half and listed all the critical features of the stone, such as the four C's, the report number, and a few security features.

The regular GIA Diamond Grading Report is a sheet of paper, 8.5"x11", which sports the same features as the Dossier. In addition, the Diamond Grading Report has a diagram showing the basic shape and cut of the diamond and labels any inclusions or blemishes found on the diamond.

The GIA has even taken to inscribing some of the more expensive diamonds with a unique Laser Inscription Registry number. This number, if present, is listed on both reports.

I highly recommend the GIA website (www.gia.org) for a graphic example of both diamond grading reports.


Liddicoat, Richard T. Handbook of Gem Identification. 11th ed. Gemological Institute of America, New York: 1981.

Gemological Institute of America Website: www.gia.org

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