![Antique Cat’s-Eye Chrysoberyl and Diamond Ring. Antique Cat's-Eye Chrysoberyl and Diamond Ring.](https://www.langantiques.com/university/wp-content/uploads/elementor/thumbs/Cats_eye_chrysoberyl-q88jzsgxyye28pd8y2njckrnygaw2yahbdf2mpulc8.jpg)
Cat’s-Eye is an optical phenomenon (also known as chatoyancy) whereby light reflects back off a gemstone, cut en cabochon, as a single ray. Extremely fine parallel inclusions in the gemstone cause a silvery ray to appear perpendicular to the orientation of the inclusions.
Cat’s-Eye is also often used to refer to the cat’s-eye variety of Chrysoberyl.