A measurement of the white light reflected up through the top of a diamond. Cutting a diamond to the correct proportions increases the reflection of all light among the facets, keeping as much of the entering light as possible, and reflects that light back to the eye of the viewer. Maximum light to the eye equals maximum brilliance.

One of the three main considerations in the beauty of a diamond:

1) brilliance

2) scintillation/sparkle

3 ) dispersion/fire