Many people confuse diamond cut with the shape of a diamond. Unlike shape, a diamond cut is the metric used to evaluate the precision and quality of the overall cutting itself. A diamond’s cut is the most complex of the 4 C’s, and not even the major labs agree on how to best measure the quality of a diamond’s cut. Diamond Cut usually takes into consideration 3 criteria: Proportions, Symmetry and Polish. Sometimes Light Performance or other tests can be used to also calculate the precision of the diamond cut.
* When a diamond is cut to proper proportions, light is reflected from one facet to another and then dispersed through the top of the stone similar to the image shown to the left.
* If the cut of the diamond is too deep, some light escapes through the opposite side of the pavilion.
* If the cut is too shallow, light escapes through the pavilion before it can be reflected.
Up until several years ago, evaluating the cut of a diamond was not an easy task. Dimensions and proportions of the diamond as well as its finish (both symmetry and polish) were all the information able to be evaluated; thereby making it difficult for consumers to understand what is described as a well-cut diamond and what is not.