Epidote
Chemical Formula	Ca2(Al, Fe)3(SiO_4)3(OH)
Species	Silicates
Crystal System	Monoclinic
Mohs Scale	6
Specific Gravity	3.4
Color	Yellowish-green, green, brownish-green, black
Streak	Colorless
Luster	Vitreous, Pearly
Refractive Index	n = 1.715 - 1.751 n = 1.725 - 1.784 n = 1.734 - 1.797
Diaphaneity	Transparent, Opaque
Cleavage	PerfectPerfect on , imperfect on
Fracture	Irregular/Uneven
Crystal Habit：Crystals prismatic to 35 cm. Fibrous, coarse to fine granular, massive.
Geological Setting：Regional and contact metamorphic rocks. Saussuritization (alteration of plagioclase)