A mineral, commonly of a yellowish green (pistachio) color, occurring granular, massive, columnar, and in monoclinic crystals. It is a silicate of alumina, lime, and oxide of iron, or manganese. [
1913 Webster]
" The Epidote group includes ordinary epidote, zoisite or lime epidote, piedmontite or manganese epidote, allanite or cerium epidote."
[1913 Webster]