Grading - Cut
diamond looks like any other rock until it is "cut" into many
facets at optimum angles to produce maximum brilliance (sparkle) and
fire (reflected colors). The quality of the cut is known as the
Marcel Tolkowsky developed the formula for the round brilliant cut
which has become the standard or "ideal" cut for diamonds.
Since then there have been various modifications and disagreement over
what constitutes the true "ideal" cut. However, the
Gemological Institute of America (GIA) has developed guidelines for
grading the make of round brilliant cut diamonds only.
two factors are the most important, and only round brilliant cut
diamonds can be rated as Class 1. The term, "ideal cut", is no
longer used by the GIA, but is still used by most of the diamond