#anorthite
- Anorthite — A mineral belonging to the silicate class, representing the pure calcium endmember of the plagioclase feldspar isomorphic series (calcium aluminum silicate). It crystallizes in the triclinic system, features a white, grayish, or reddish color, and is a common structural constituent in basic and ultrabasic igneous rocks (such as gabbros and basalts), as well as in some metamorphic rocks or meteoritic materials.