GIA FAQs

Q. What is Cut?

A. The mere fact that there are traditionally 58 tiny facets in a diamond, each carefully cut and sharply defined, and may be only two millimeters in diameter, strikes many in the buying public as little short of miraculous. But this precision is essential to the potential beauty of a diamond. As a matter of fact, overall appearance – the brilliance, fire, and scintillation that makes diamonds uniquely beautiful – depends more on cut than anything else. There are no internationally recognized grades for cut, as there are for color and clarity, and ther are differences of opinion within the trade about some aspects of cut. Even the Federal Trade Commission is vague about it, compared to the rigor with which other aspects of diamond quality are described. But the affect of cut on a diamond's appearance is indisputable. The Gemological Institute of America (GIA) describes cut as the proportions and finish of a diamond or colored stone. Proportions are the size and angle relationships between the facets and different parts of the stone. Finish includes polish and details of facet shape and placement. Cut can also mean shape, as in round brilliant, emerald cut, or marquise cut.