Cat's Eye Explained: Exploring Chatoyancy in Gemstone Phenomena

Intrigued by gemstones with a hidden light? Have you ever been captivated by a gemstone that seems to hold a mysterious light within? That captivating, silky sheen that dances across its surface like a watchful cat's eye is a fascinating phenomenon called chatoyancy. Here at Aster Gemological, our gemologist Howe Wei can shed some light on the science behind this mesmerising effect!

​The Science Behind the Shine of ChatoyancyThe word "chatoyancy" comes from the French "oeil de chat," meaning "cat's eye." This aptly describes the effect, which occurs due to the presence of tiny, parallel, hollow tubes or fibers within a gemstone. These microscopic structures, often referred to as "silk," act like miniature light guides. When light hits the gem, it travels through these tubes and reflects off their walls, concentrating into a beam that appears as a luminous band across the stone's dome.