Diamonds used to be cut in more rectangular shapes until the 19th century when the shapes got
rounder and the cut more symmetrical. The two optical properties that make diamonds so special
are brilliance and dispersion, and both of them are affected by the cut. Brilliance is the brightness
created by the light reflections from the faceted surfaces of a polished diamond and dispersion is the
separation of white light into the colors of the rainbow, seen as flashes of color. Old cut diamonds
show more dispersion and slightly less brilliance than the brilliant cut diamonds of today. The charm
of these diamonds are the fantastic color flashes and the unique hand cut shapes.