Define crown height percentage.

Define crown height percentage.

• A. The height of the crown measured in millimeters.
• B. The distance from the girdle plane to the table, expressed as a percentage of average girdle diameter.
• C. The percentage of the diamond's weight attributed to the crown.
• D. The height of the girdle relative to the table.

Answer: (C)

Crown height percentage is the crown height—the distance from the girdle plane up to the table—expressed as a percentage of the average girdle diameter. This ties how tall the crown is to the stone’s overall width, influencing how light is returned and how the cut appears. For example, if the crown height is 2 mm and the average girdle diameter is 6 mm, the crown height percentage is (2/6) × 100 = 33.3%. The other options describe measurements in millimeters, a relation involving the girdle rather than height, or weight distribution, none of which define crown height percentage.

Crown height percentage is the crown height—the distance from the girdle plane up to the table—expressed as a percentage of the average girdle diameter. This ties how tall the crown is to the stone’s overall width, influencing how light is returned and how the cut appears. For example, if the crown height is 2 mm and the average girdle diameter is 6 mm, the crown height percentage is (2/6) × 100 = 33.3%. The other options describe measurements in millimeters, a relation involving the girdle rather than height, or weight distribution, none of which define crown height percentage.