Antlerite
Chemical Formula	Cu3(SO4)(OH)4
Species	Sulfates
Crystal System	Orthorhombic
Mohs Scale	3
Specific Gravity	3.9
Color	Bright green, through darker greens to black
Streak	Pale green
Luster	Vitreous
Refractive Index	n = 1.726 n = 1.738 n = 1.789
Diaphaneity	Translucent
Cleavage	PerfectPerfect on , poor on .
Fracture	Uneven
Crystal Habit：tabular and acicular or fibrous. Also found as reniform, massive or granular specimens
Geological Setting：In weathered zones of carbonate-poor copper deposits in arid regions