Cut refers to the proportions and finish of a diamond, the factors which determine the diamond's sparkle and fire. Shape simply refers to the outline of the diamond looking from the top down. It is possible to have two diamonds of the same shape, carat size, color and clarity, which appear completely different due to slight variations in cut.

 

Diamond beauty and performance is unveiled when light enters through the top (or crown) of the stone, bounces around inside the lower facets and finally exits through the crown. This produces a rainbow of colors and sparkling effect, by returning as much light to the eye as possible. To obtain this effect, diamonds must be cut to exacting parameters often sacrificing weight.

 

The American Gem Society Laboratories was the first lab to provide cut grading for round brilliant diamonds, protecting consumers with an independent, unbiased and complete analysis of all the factors that determine beauty and value. The AGS Lab is currently conducting research to expand its consumer-friendly cut-grading system to include other diamond shapes.