Osarizawaite

Osarizawaite is a greenish yellow sulfate mineral with the chemical formula: PbCuAl₂(SO₄)₂(OH)₆. It has rhombohedral crystals.^[5]

Osarizawaite
Osarizawaite from Arizona
General
Category	Sulfate minerals, alunite group
Formula	PbCuAl2(SO4)2(OH)6
IMA symbol	Orz[1]
Strunz classification	7.BC.10
Crystal system	Trigonal
Crystal class	Hexagonal scalenohedral (3m) H-M symbol: (3 2/m)
Space group	R3m
Unit cell	a = 7.05, c = 17.24(1) [Å], Z = 3
Identification
Color	Greenish yellow
Tenacity	Brittle
Mohs scale hardness	3 - 4
Specific gravity	3.89 - 4.037
Optical properties	Uniaxial (+)
Refractive index	nω = 1.712() nε = 1.732(2)
Birefringence	δ = 0.020
Pleochroism	Visible
References	[2][3][4]

It was first described in 1961 for an occurrence in the oxidized zone of the Osarizawa mine, Akita Prefecture, Honshu Island, Japan.^[2]