CERVANTITE

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Orthorhombic
    Chemistry : Sb2O4
    Rarity : Uncommon

Cervantite is a secondary mineral typical of stibnite alteration, known in the surface oxidation zone of antimony deposits. it was named thus in reference to its supposed locality of discovery : Cervantes (Spain). It sometimes appears in prismatic crystals, more commonly in powdery coatings, yellow to yellow-brown, sometimes orange-brown. Its density is high for an antimony mineral (6.5). It is sometimes used as antimony ore, notably in Sensa (Algeria).

Main photo : Cervantite pseudomorph after stibnite from Gallos Mine, Zacatecas, Mexico © John Sobolewski

Cervantite of Cetine, Tuscany, Italy © Enrico Bonacina
Cervantite from the Clara Mine, Freiburg, Germany © Stephan Wolfsried
Cervantite from the La Forge Mine, Puy-de-Dôme, France © Pascal Chollet
Cervantite from the Clara Mine, Freiburg, Germany © Stephan Wolfsried

Cervantite in the World

The crystals, acicular, are extremely rare. The best samples come from Baia Sprie (Romania), Cetine (Tuscany, Italy), and especially San José (San Luis Potosi, Mexico) where cervantite occurs in lamellar pseudomorphs of large stibnite crystals. Cervantite was abundant in the Algerian deposit of Sensa, where it constituted with valentinite the majority of antimony ore.

Cervantite in France

In France, cervantite is reported at the La Forge mine near Issoire (Puy-de-Dôme), at the Chalanches mine (Isère), at the Plessis quarry (Finistère), at Lussac (Charente) and at the Biards mine (Haute-Vienne).

Twinning and special crystallizations

No twin known for this mineral species.

Fakes and treatments

No fake identified for this mineral species.


Hardness : 4 to 5
Density : 6.5
Fracture : Irregular
Streak : White to yellow

TP : Translucent
RI : 2.000 to 2.100
Birefringence : 0.100
Optical character : Biaxial
Pleochroism : None
Fluorescence : None

Solubility : -


Magnetism : None
Radioactivity : None