Onyx is a banded variety of the oxide mineral chalcedony. The colors of its bands range from white to almost every color (with the exception of some shades, such as purple or blue). Commonly, specimens of onyx contain bands of black and/or white.
Cat's Eye Translucent yellowish chatoyant chrysoberyl is called cymophane or cat's eye. Gems lacking the silky inclusions required to produce the cat's eye effect are usually faceted. An alexandrite cat's eye is a chrysoberyl cat's eye that changes color.