*** Welcome to piglix ***

Tellurite

Tellurite
Tellurite-214977.jpg
Tellurite from the Moctezuma Mine, Moctezuma, Sonora, Mexico
General
Category Oxide minerals
Formula
(repeating unit)
TeO2
Strunz classification 4.DE.20
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Pbca
Unit cell a = 5.6 Å, b = 12.03 Å
c = 5.46 Å; Z = 8
Identification
Color Yellow to white
Crystal habit Flattened prismatic to acicular crystals, radiating groups; powdery, massive
Cleavage Perfect on {010}
Tenacity Flexible
Mohs scale hardness 2
Luster Sub-adamantine
Diaphaneity Transparent to opaque
Specific gravity 5.88 - 5.92
Optical properties Biaxial (-)
Refractive index nα = 2.000 nβ = 2.180 nγ = 2.350
Birefringence δ = 0.350
Solubility Sleight in water
References

Tellurite is a rare oxide mineral composed of tellurium dioxide (TeO2).

It occurs as prismatic to acicular transparent yellow to white orthorhombic crystals. It occurs in the oxidation zone of mineral deposits in association with native tellurium, emmonsite and other tellurium minerals. Its name comes from Tellus, which is the Latin name for the planet Earth.

It was first described in 1842 for an occurrence in Faţa Băii, Zlatna, Alba County, Romania.


...
Wikipedia

...