17 Photos
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

Antlerite is a greenish hydrous copper sulfate mineral, with the formula Cu₃(SO₄)(OH)₄. It occurs in tabular, acicular, or fibrous crystals with a vitreous luster. Originally believed to be a rare mineral, antlerite was found to be the primary ore of the oxidised zones in several copper mines across the world, including the Chuquicamata mine in Chile, and the Antler mine in Arizona, USA from which it takes its name. It is chemically and optically similar in many respects to other copper minerals such as malachite and brochantite, though it can be distinguished from the former by a lack of effervescence in hydrochloric acid.