Epidote group | |
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General | |
Category | Sorosilicates |
Formula (repeating unit) | (A2+1A2+2)(M3+1M3+2M3+3)O[Si2O7][SiO4](OH) |
IMA symbol | Ep |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H–M symbol) |
Space group | P21/m |
Identification | |
Color | Yellow-green, pistachio green, greenish black, brownish-green, green, black |
Crystal habit | Prismatic, fibrous, druse/encrustation, massive |
Twinning | On [100] |
Cleavage | {001} perfect and {100} imperfect |
Mohs scale hardness | 6–7 |
Luster | Vitreous |
Epidotes are a group of sorosilicate minerals that are common in igneous and metamorphic rocks.[1][2][3]