Cervantite
| Cervantite | |
|---|---|
| 
 
 Microscopic cervantite crystals from Slovakia (3 mm field of view)  | |
| General | |
| Category | Oxide mineral | 
| Formula  (repeating unit)  | Sb3+Sb5+O4 | 
| Strunz classification | 04.DE.30 | 
| Crystal system | Orthorhombic | 
| Space group | 
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 | 
| 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
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