Cervantite

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

Cervantite
Microscopic cervantite crystals from Slovakia (3 mm field of view)
General
CategoryOxide mineral
Formula
(repeating unit)
Sb3+Sb5+O4
Strunz classification4.DE.30
Crystal systemOrthorhombic
Crystal classPyramidal (mm2)
(same H-M symbol)
Space groupPbn21
Unit cella = 5.43 Å, b = 4.81 Å,
c = 11.76 Å; Z = 4
Identification
ColorYellow to nearly white
Crystal habitMicroscopic acicular crystals; massive
CleavageExcellent on {001}, distinct on {100}
FractureConchoidal
Mohs scale hardness4–5
LusterGreasy, pearly, earthy
StreakPale yellow to white
DiaphaneitySemitransparent
Specific gravity6.5
Optical propertiesBiaxial
Refractive indexnα = 2.000 nγ = 2.100
Birefringenceδ = 0.100
Dispersionrelatively weak
References[1][2][3][4]

It was first described in 1850 for an occurrence in Cervantes, Sierra de Ancares, Lugo, Galicia, Spain, and named for the locality.[3] The mineral was questioned and disapproved, but re-approved and verified in 1962 based on material from the Zajaca-Stolice district, Brasina, Serbia.[2] It occurs as a secondary alteration product of antimony bearing minerals, mainly stibnite.[2]

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

References

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