euclase

noun

eu·​clase ˈyü-ˌklās 

-ˌklāz

: a mineral that consists of a brittle silicate of beryllium and aluminum in pale yellow, green, or blue prismatic crystals and is used especially as a gemstone

Word History

Etymology

French, from eu- (from Latin) + Greek klasis breaking, from klan to break

First Known Use

1804, in the meaning defined above