Any of several gemstones that display a luminous band reminiscent of the eye of a cat.
Grayish green or greenish quartz cat's-eye is the most common type; although it comes from the Orient, it is often called occidental cat's-eye to differentiate it from the rarer, and more valuable, precious or oriental cat's-eye, which is a greenish variety of chrysoberyl. Crocidolite cat's-eye (African cat's-eye) is more commonly known as tigereye . Corundum cat's-eye is an imperfect star sapphire or ruby in which the star is reduced to a luminous zone.
Chrysoberyl cat's-eye with yellow banding on a brown stone
John H. Gerard