Jarosite
Chemical Formula	KFe3+3(OH)6(SO4)2
Species	Sulfates
Crystal System	Trigonal
Mohs Scale	2-3
Specific Gravity	2.9-3.3
Color	Amber yellow or dark brown
Streak	light yellow
Luster	Sub-Adamantine, Vitreous, Resinous
Refractive Index	n = 1.815 - 1.820 n = 1.713 - 1.715
Diaphaneity	Translucent
Cleavage	Distinct/GoodDistinct on .
Fracture	Irregular/Uneven, Conchoidal
Crystal Habit：Crystals are usually pseudocubic or tabular, also as granular crusts, nodules, fibrous masses or concretionary.
Geological Setting：A secondary mineral found in the oxidized zones of sulfide deposits, forming by the reaction of dilute sulfuric acid in ground water, derived from the oxidation of pyrite, with gangue minerals and wall rock in the deposits.