Family of silicate minerals containing mostly calcium, aluminum, iron and magnesium along with water. Epidote is apple green and generally forms very small, stubby, prismatic crystals. It often occurs in veins or as a green coating on fracture surfaces. Most common in metamorphic rocks, but occasionally forms in igneous pluton s that crystallize very deep in the crust.
Epidote is a calcium aluminium iron sorosilicate mineral, Ca2(Al, Fe)3(SiO4)3(OH), crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often deeply striated and crystals are often twinned.