Estimating Pavilion Angle (5.15)
The preferred pavilion angle of 40.75° corresponds to a pavilion depth percentage of approximately 43%. Again this is important to bear in mind for understanding preferred depths and for communicating these facts to other dealers or to retail clientele. In the figure below, note the relationship of flatter and steeper angles to the corresponding depth percentages. In addition to correct pavilion angles, consistent pavilion angles are also important to achieve proper symmetry on the finished diamond. You will often see diamonds with off-center culets. This is caused by the cutter’s choice in leaving the pavilion angles inconsistent. For example, one side is 39.5˚ and its opposite is 42.5˚ allowing the culet to favor the higher angled side.
