Diamond Brilliance

Cut in a cone shape with many facets that results in maximal light return through the top. Rarely less than 50% of the diamond is removed. The Source of the Diamond's Brilliance Modern diamonds has 58 facets (faces) and are shaped like two pyramids sitting base to base with a thin "girdle" separating them. The top pyramid (crown) has a large inner table surrounded by three circles of facets, an inner circle of 8 (star) facets, a middle circle of 16 (kite) facets and an outer circle of 16 (upper girdle) facets. The lower pyramid (pavilion) consists of one cutlet (a small central circle located at the apex) surrounded by a circle of 8 (pavilion) facets that are surrounded by a circle of 16 (lower girdle) facets. In recent years diamond cutters have begun adding as many as 96 facets or more to the surrounding girdle, but these are not counted as official facets. The brilliance of the diamond depends on the polish and alignment of the facets, the crown angle, pavilion angle, table size, and length of the lower facets. Absorbed light can reflect off any facet, so the path light follows within the diamond is complex. The understanding of how best to arrange the facets so as to maximize light return has grown more and more complex. Several groups have developed grading standards that best describe the gem cutters success at maximizing light return when the distance to the viewer's eye is anywhere from 10 – 16 inches. All experts agree that optimal face placement is the key to brilliance.