1. A luminous optical effect in certain gemstones, such as cat's eye or tiger's eye, in which a bright band of light appears to move across the surface as the stone is turned.
Usage: gemology term; from French chatoyer, meaning 'to shimmer like a cat's eye'

Examples

• The chatoyance of the tiger's eye stone made it shimmer beautifully under the light.
• Jewelers prize chatoyance as a desirable quality in certain gemstones.
• The cat's eye ring displayed a striking chatoyance that seemed to glow from within.
• Chatoyance occurs when light reflects off parallel fibers or inclusions within the stone.
• The gemstone's chatoyance was most visible when held up to natural sunlight.