Cervantite

Cervantite
Cervantite

Microscopic cervantite crystals from Slovakia (3 mm field of view)
General
Category Oxide mineral
Chemical formula Sb3+Sb5+O4
Strunz classification 4.DE.30
Crystal symmetry Orthorhombic pyramidal
H-M symbol: (mm2)
Space group: Pbn21
Unit cell a = 5.43 Å, b = 4.81 Å, c = 11.76 Å; Z = 4
Identification
Color Yellow to nearly white
Crystal habit Microscopic acicular crystals; massive
Crystal system Orthorhombic
Cleavage Excellent on {001}, distinct on {100}
Fracture Conchoidal
Mohs scale hardness 4–5
Luster Greasy, pearly, earthy
Streak Pale yellow to white
Diaphaneity Semitransparent
Specific gravity 6.5
Optical properties Biaxial
Refractive index nα = 2.000 nγ = 2.100
Birefringence δ = 0.100
Dispersion relatively weak
References [1][2][3]

Cervantite is an antimony oxide mineral with formula Sb3+Sb5+O4 (antimony tetroxide).

It was first described in 1850 for an occurrence in Cervantes, Sierra de Ancares, Lugo, Galicia, Spain, and named for the locality.[2] The mineral was questioned and disapproved, but re-approved and verified in 1962 based on material from the Zajaca-Stolice district, Brasina, Serbia.[1] It occurs as a secondary alteration product of antimony bearing minerals, mainly stibnite.[1]

Cervantite and valentinite replacing stibnite from the Xikuangshan Mine of Hunan Province, China (size: 16.1 x 5.0 x 3.0 cm)

References