Labradorite

Labradorescence is the distinctively strong reflection, or "schiller", seen in labradorites. Schiller is a characteristic of feldspars, including Moonstone and Oregon Sunstone.  It is a glow that looks as if the stone is lit from inside. In Labradorite it is so striking that people refer to it as "flash". Generally, the stronger and more multi-directional the flash is, and the more beautiful the color is, the better--and more expensive to obtain--the stone is.

These stones are graded by quality for pricing purposes and numbered for identification. (The grades are mine, not GIA) Photos are not to scale. Dimensions are in the descriptions.  "A+" stones are generally larger and the flash is striking and equally visible from all directions. "A" stones are generally smaller and the flash is bright but not equal from all directions. B stones show good color and flash as they move.