Scrabble?! CHATOYANCE

Definitions of CHATOYANCE in various dictionaries:

In gemology, chatoyancy ( sh-TOY-n-see), or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones. Coined from the French "il de chat", meaning "cat's eye", chatoyancy arises either from the fibrous structure of a material, as in tiger's eye quartz, or from fibrous inclusions or cavities within the stone, as in cat's eye chrysoberyl. The precipitates that cause chatoyance in chrysoberyl are the mineral rutile, composed mostly of titanium dioxide. Examined samples have yielded no evidence of tubes or fibres. The rutile precipitates all align perpendicularly with respect to cat's eye effect. It is reasoned that the lattice parameter of the rutile matches only one of the three orthorhombic crystal axes of the chrysoberyl, resulting in preferred alignment along that direction. The effect can be likened to the sheen off a spool of silk: The luminous streak of reflected light is always perpendicular to the direction of the fibres. For a gemstone to sho