The crown angle of a diamond is formed by the girdle plane and the:

The crown angle of a diamond is specifically formed by the girdle plane and the bezel facets. Bezel facets are the angled facets located above the girdle that contribute to the crown of the diamond and play a vital role in its overall appearance and brilliance. The angle created between the girdle (the diamond's widest part) and the bezel facets affects how light interacts with the stone, influencing its sparkle and visual appeal.

Understanding the crown angle is essential for assessing a diamond's proportions and light performance. The proper crown angle helps maximize the diamond's ability to refract light, enhancing its overall brilliance and fire.