|a green mineral consisting of hydrated calcium iron aluminium silicate in monoclinic crystalline form: common in metamorphic rocks. Formula: Ca2(Al,Fe)3(SiO4)3(OH)|
|[C19: from French épidote, ultimately from Greek epididonai to increase, from didonai to give; so called because two sides of its crystal are longer than the other two sides]|
|epidote (ěp'ĭ-dōt') Pronunciation Key
A yellowish-green or blackish-green monoclinic mineral. Epidote occurs as formless grains or as prism-shaped crystals, and is found in limestones that have undergone slight metamorphism or in igneous rocks. Chemical formula: Ca2(Al, Fe)3(SiO4)3OH.