Cat's eye phenomenon or chatoyancy is caused by light reflecting off of parallel bundles of tiny hollow tubes or fibrous crystals of another mineral inside the gemstone.
Emerald cat's eye is very rare and only found in emeralds from Brazil or Columbia.
This sharp cat's eye emerald, alexandrite, and diamond ring was priced of $US 53,000 at Sotheby's Magnificent jewels & jadeite auction.
