Urusovite

Urusovite
General
Category Arsenate mineral
Formula
(repeating unit)
CuAlAsO5
Strunz classification 08.BB.60
Dana classification 38.05.09.02
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: P 21/c
Unit cell a = 7.314 Å, b = 10.223 Å, c = 5.576 Å; β = 99.79°; Z = 4
Identification
Color Light green
Crystal system Monoclinic
Cleavage Perfect
Fracture Brittle
Mohs scale hardness 4
Luster Vitreous (Glassy)
Streak White
Diaphaneity Translucent
Optical properties Biaxial (-)
Refractive index nα = 1.672 nβ = 1.718 nγ = 1.722
Birefringence δ = 0.050
Dispersion r > v strong
References [1][2]

Urusovite is a rare copper aluminium arsenate mineral with formula: CuAlAsO5. It is a monoclinic-prismatic light green mineral.

Its type locality and only reported occurrence is in the Novaya fumarole, Second scoria cone, North Breach, Great Fissure eruption, Tolbachik volcano, Kamchatka Oblast', Far-Eastern Region, Russia.[1][2] It was named after Vadim Sergeevich Urusov, crystal chemist of Moscow State University.[3] It was approved by the International Mineralogical Association in 1998.[1]

References