1990s

Why diamond grades begin with "D" & not A, B, C?

March 1998

It is a great mystery to the general public and to some in the industry: Why do diamond color grades begin with "D"?

Perhaps to most effectively drive home the point that diamonds are in a class by themselves.
That, at least, would seem to be the explanation implied in a recent letter to Gem & Jewelry News, published by the Gemological Association of Great Britain.

The letter, penned by Gemological Institute of America Chairman Richard Liddicoat, who was there when the grading system was developed, said that the old diamond grading systems — using terms like "top Wesselton" and "river" — had fast become commercially tainted. Retailers began luring customers with promises of "extra" or even "extra, extra, extra River stones," he recalled.

The solution was to create a grading system that did not echo any popular associations which could then be co-opted by any firm or firms seeking to unfairly exploit these associations.

"It was obvious that to establish a grading system for use in the jewelry industry, the grades could not have consumer appeal," he said. Thus, the reason why diamond grades begin with ‘D.’ In America, at least ‘D’ had a very poor connotation. ‘E,’" a failing academic grade, could also be short for ‘excellent,’ but not ‘D.’ It worked," the writer noted.