DIAMOND EDUCATION

GIA Diamond Certification

Origins
The Gemological Institute of America (GIA), founded in Los Angeles in 1931, is an independent, non-profit organization considered by many to be the world’s foremost authority in gemology. In 1953, the GIA created its International Diamond Grading System, which specifies uniform criteria for grading diamonds. The GIA grading system is recognized worldwide, and diamond manufacturers from around the globe send diamonds to the GIA’s laboratories for examination and grading. Even the White House has trusted the GIA for answers to diamond-related questions. A GIA Diamond Grading Report is the most widely understood and trusted set of credentials that can accompany a diamond.

GIA Diamond Grading Report and Diamond Dossier

Methodology
Triple redundancy: grade it, grade it, and grade it again. Two to five highly trained gemologists examine each diamond in the process of preparing a GIA Grading Report.

• Weight and measure are determined, and the stone’s culet and girdle thickness are described.
• Color is graded by comparing the diamond to master stones of predetermined color.
• Clarity is assessed based on an examination of the stone under a binocular microscope of 10x magnification. Clarity characteristics are plotted on a diamond diagram.
• Polish and symmetry grades are assigned according to an inspection of the diamond’s craftsmanship.

In some cases, additional, highly experienced gemologists review all the grading information and independently render their judgments of color, clarity, polish, and symmetry. Grading results are finalized after a sufficient number of agreeing opinions have been rendered.

View an example of the GIA Grading Report and the Diamond Dossier.

Cut Grade
The GIA cut grade of a diamond is determined on an assessment of seven factors. The first four-polish, symmetry, weight ratio, and durability-refer to the make of the diamond. The remaining three-brightness, scintillation, and fire-describe the appearance of each brilliant round-cut diamond.

The GIA grades brilliant round-cut diamonds on a five-step scale.

GIA Gem Laboratory
580 Fifth Avenue, Suite 200
New York, New York 10036
www.gia.edu