Chatoyant

a. [Fr. chatoyant, p. pr. of chatoyer, from chat, cat.] (Min.) Having a changeable, undulating luster, or color, like that of a cat's eye in the dark. Dana.

n. (Min.) A hard stone, as the species of chalcedony called cat's eye, which, when cut and polished, presents on its surface, and in the interior, an undulating or wavy light. Dana.