If the crown angle is too large, sparkle will be limited when viewed from above. If the crown angle is too small, the top of the diamond could appear clear and glassy. Diamonds cut with an optimal angle will yield more sparkle.

A typical round brilliant diamond has 33 facets on the crown and, if well proportioned, these will be uniform and aligned for maximum sparkle. Because these proportions are considered when the diamond's cut grade is being assessed, an Ideal or Very Good cut grade is enough of an indicator to be sure that a diamond's crown is shaped well.

Fancy diamond shapes all have slightly different styles of crown. In an emerald or asscher-cut diamond, for example, the crown is cut with much fewer facets than a round or other brilliant patterned stone. This typically results in less dispersion, but the cuts are prized for their emphasis on clarity and geometrical symmetry.

The quality of a diamond's crown is not recorded on a grading report by itself. The GIA and AGSL list the crown angle and crown height, which are factored into its overall cut grade. Most round diamonds will have a crown angle of between 30 and 35 degrees. The crown angle for a round Ideal cut diamond must be between 33.7 and 35.8 degrees. Shallower diamonds will create a flat effect that loses fire.