The secret of a diamond that is properly cut is that it returns a measurably greater amount of light, which is displayed as brilliance, dispersion and scintillation.
This is the true measure of a diamond's beauty.
Brilliance: The total amount of white light, both external and internal, returned from
the diamond to the eye of the observer.
Dispersion: Flashes of color, or fire, particularly when viewing a diamond in strong,
direct light.
Scintillation: Reflections and flashes of white light from the diamond's surface as the
diamond, observer or light source moves.
