There are a number of different types of Chatoyancy. Simple Chatoyancy is caused by microscopic needles reflecting light back to the eye. Cat's Eye happens when the needles are well organized in a single band. Asterism, Star chatoyancy is similar to cat's eye chatoyancy but the bands align along 2 or more axis points. 4 and 6 ray stars are common. Adularescence is the play of light seen in stones like Moonstone & Labradorite. Adularescence is caused by the layered structure of these gemstones. The term aventurescent is found in material like Aventurine. This effect is caused by the reflection of light from tiny disc-like inclusions, typically composed of mica, copper or hematite. The terms schiller and sheen are very often used to describe aventurescence.