a rare very hard greenish-yellow mineral consisting of beryllium aluminate in orthorhombic crystalline form and occurring in coarse granite: used as a gemstone in the form of cat's eye and alexandrite. Formula: BeAl2O4
chrysoberyl in American English
(ˈkrɪsoʊˌbɛrɪl; ˈkrɪsəˌbɛrɪl)
noun
a very hard, yellowish or greenish mineral, BeAl2O4, used as a gem; beryllium aluminum oxide