GIA polls industry about diamonds. (Trade Notes).

Using a groundbreaking approach to the evaluation of diamond appearance, research scientists at the Gemological Institute of America (GIA) have studied how human observers describe and judge diamonds of various proportions under a variety of conditions. Diamond dealers, retailers, consumers, and trained observers have all taken part in this ongoing series of observation tests of diamond appearance.

Over an 18-month period, GIA collected nearly 40,000 observations of more than 1,000 diamonds in a variety of controlled environments, as well as in typical trade settings. No cut-evaluation methodology currently used in the trade has been empirically tested in this manner. …