Many people confuse cut with the shape of a diamond.
Most diamonds are cut round with a full 58 facets, and a good cut, or make,
has more scintillation, more sparkle.
Table & depth percentages are key to determining good proportions.
The cut, or proportions, of a diamond is measured in percentages relative to the diameter of its girdle. The girdle diameter of each diamond is always considered 100%.
Example: The girdle of a diamond measures 10 millimeters (100%). The table measures 5.6 millimeters. The total depth measurement is 6.1 millimeters. The diamond would be described as having a table of 56% and a depth of 61%.