In gemology, chatoyancy, or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones, woods, and carbon fibre.

What is chatoyancy in wood?

In gemology, chatoyancy (/ʃəˈtɔɪ. ənsi/ shə-TOY-ən-see), or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones, woods, and carbon fibre.

What color is chatoyancy?

It has greenish yellow color that makes it even more similar to feline eyes. Chatoyancy is traditionally attributed to tiny needles of exsolution rutile, although other mineral species can be also involved. These inclusions are so thin that they are not distinguishable to the naked eye and even through 10x loupe.