Even though this diamond measures an acceptable 63% depth the crown and pavilion angles are far from acceptable. A deep pavilion and a flat crown could portray a deceiving favorable depth percentage.

The pavilion angle or depth will also have to be addressed to determine either a properly proportioned diamond, or a diamond that will need re-cutting. In a mounting, the Table Reflection Method is especially helpful in determining pavilion angle/depth. Frequently there is an opening in the mounting beneath the culet, which enables a direct measurement of the overall depth (table to culet). It is common to find that the cutter left a steep crown and/ or pavilion angles in order to attain a higher weight category.

You also know a pavilion is deep when the overall depth is 63%+ with a shallow crown. Example: Visually you determine a flat crown by viewing the side profile of the diamond and a normal, medium girdle. Using your Leveridge Gauge the diamond in question measures: 6.72 mm in width and 4.62 mm in depth. To get the overall depth percentage you then divide 4.62 mm by 6.72 mm which equals .6875 or 68.8% depth. Needless to say this is considered a very deep stone for a round brilliant. The only characteristic left by which to achieve this depth would be very steep pavilion angles. In this extreme case, the diamond will show considerable center darkness.