TELLURITE

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Orthorhombique
    Chemistry : TeO2
    Rarity : Very rare

Tellurite is a very rare tellurium mineral, dimorphic of paratellurite, found in the oxidation zone of epithermal gold deposits, where it comes from the oxidation of tellurium minerals. Tellurite is often closely associated with native tellurium, native gold, and various tellurides (hessite, sylvanite, altaite) and sulfides (sphalerite, galena, pyrite). The name of this mineral reflects its chemical composition. Tellurite forms small, flattened, striated, acicular crystals, frequently grouped into radiate spherulites or tufts, or powdery masses, white, yellow, sometimes orange in color.

Main photo : Tellurite from Moctezuma Mine, Sonora, Mexico © Joy Desor

Tellurite from Moctezuma Mine, Sonora, Mexico © Elise Chaigneau & Eric Penet
Tellurite from Moctezuma Mine, Sonora, Mexico © Elmar Lackner
Tellurite from Mariahilf Mine, Zlatna, Romania © Stephan Wolfsried
Tellurite from Tintic, Utah, USA © Alex Earl

Tellurite in the World

Superb 3 cm crystals, the largest known, come from the gold and silver veins of Moctezuma (Mexico). The Romanian gold mines of Transylvania (Sacarimb, Zlatna) and Colorado (Cripple Creek, Central City, Vulcan) have also provided very beautiful specimens of this mineral. Tellurite is also known in the Japanese deposits of the Teine and Shimoda districts.

Tellurite in France

In France, tellurite is reported in the burning slag heaps of La Ricamarie near St-Etienne (Loire).

Twinning

No twinning known for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 2
Density : 5.88 to 5.92
Fracture : Undetermined
Streak : White

TP : Transparent
RI : 2.000 to 2.350
Birefringence : 0.350
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : Nitric acid, hydrochloric acid, water

Magnetism : NoneRadioactivity : None