This gem, whit its band of reflected light across the middle, has always reminded observers of the eye of a cat. The cats-eye effect, also called chatoyancy, is caused by parallel needle-like inclusions within the stone. The gem was once known as cymophane Greek for waving light. In some cultures, its distinctive appearance made it the preferred treatment for all sorts of eye ailments.Chatoyancy appears in other gemstones, But fine-quality cats-eye chrysobery1 sets the standard. Its also the most valuable Cats eye stone. Its durable as well as attractive, which makes it popular in mens Rings, cufflinks and tie tacks. The cabochon cut brings out its cats eye effect to best advantage.Cats eye display another impressive Effect, called milk and honey. With the light positioned perpendicular to the Chatoyant band, the side nearest the light shows the stones original bodycolor while The other side has a milky appearance.