Argentojarosite

Argentojarosite is an iron sulfate mineral with the chemical formula AgFe³⁺₃(SO₄)₂(OH)₆. It is one of few iron sulfate minerals containing silver in its chemical formula as a dominant element.^[2] Its type locality is the East Tintic Mountains, Utah.^[2][3]

Argentojarosite
Argentojarosite found in Sonora, Mexico
General
Category	Sulfate mineral
Formula	AgFe3+3(SO4)2(OH)6
IMA symbol	Agjrs[1]
Strunz classification	7.BC.10
Dana classification	30.2.5.5
Crystal system	Trigonal
Crystal class	Ditrigonal pyramidal (3m)
Space group	R3m
Identification
Color	Yellow, yellow-brown, brown
Crystal habit	Coatings, fine-grained masses
Cleavage	{0001} distinct
Mohs scale hardness	3.5-4.5
Luster	Vitreous
Streak	Light yellow
Specific gravity	3.66
Density	3.66 (measured), 3.81 (calculated)
Optical properties	Uniaxial (-)
Pleochroism	Dichroic, O: Yellow, E: Pale yellow
References	[2][3]