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Identifying Gemstones: Are They Real?

MARCH 31, 2016  |  STAPLES ROOM  |  10:30AM-12:00PM

A wide variety of natural, synthetic, treated, and imitation gem materials are available and have a proper place in today's jewelry market.  Maintaining consumer confidence in gems and jewelry purchases requires correct identification, proper information disclosure, and appropriate pricing of these gem materials by jewelers.

GIA is a non-profit educational institute that serves the public and the jewelry industry with correct information on gemstones.  Since its founding in 1931, GIA has provided professional gemological education to tens of thousands of students worldwide.

The GIA Laboratory was established in 1949 as a facility for the testing of pearls and other gem materials.  The first diamond grading reports were issued in 1955 based on a quality evaluation system called the "4 C's" (carat weight, color, clarity and cut) that had been developed by GIA experts.  This system has since become the international standard for evaluating the quality of polished diamonds, and thousands of grading reports are issued annually by the Laboratory.  Identification reports are provided for pearls and other gem materials. The public often hears advertising that proclaims that someone sells GIA-graded diamonds.

While gemological research has been an essential activity at the Institute since the mid-1930s, the GIA Research Department was formally created in 1976.  While many gem materials can be recognized by a GIA-trained gemologist, others present difficulties for identification especially when the synthesis or treatment processes used simulate conditions that natural gemstones could be exposed to in the earth.  GIA scientists currently use a variety of advanced scientific instrumentation to systematically document the properties of gem materials to establish a basis for their identification.

The presentation will review: some of the practical training for careers that GIA provides; areas of research at GIA; resources used by GIA; data gathering from original locations; diamond cut quality research; and a focus on challenges related to distinguishing natural versus artificial growth, color and clarity treatment processes.



Dr. James Shigley
is a distinguished research fellow at the Gemological Institute of America in Carlsbad, California.  Prior to joining GIA in 1982, he studied geology as an undergraduate at the University of California, Berkeley, and later received his doctorate in geology from Stanford University.  He helps direct GIA's research activities on the identification of diamonds and colored gemstones, and has an ongoing research interest in the environments of gem mineral formation in pegmatites and other host rocks.

Al Gilbertson
is the manager of GIA's Cut Research in Carlsbad CA. After a distinguished career as a jewelry appraiser and gem cutter, GIA hired him in 2000 to be part of GIA's team researching diamond cut evaluation. He is one of GIA's researchers that created GIA's cut grading system for the round brilliant diamond. He is currently studying the influence of proportions and other factors on the appearance of fancy shape diamonds.