An ideal cut diamond reflects almost all the light that enters it, and is among the rarest cuts. The terms to diamond’s cut are: Fire, Brilliance, and Scintillation. Fire refers to the light dispersion that appears as flashes of rainbow colors. Brilliance refers to the light reflected in and out of the diamond. Scintillation speaks to the pattern of dark and light facets that intensely sparkles when the diamond is moved.