Tungstite
Tungstite is a hydrated tungsten oxide mineral with the chemical formula WO3·H2O. It is typically found as an alteration product of other tungsten-bearing minerals such as wolframite and scheelite, occurring in the oxidized zones of tungsten deposits.
Properties: Tungstite is usually yellow to yellowish-green in color, though it can also be brown or white. It is a soft mineral, with a Mohs hardness of around 2.5. The luster is typically earthy or dull. Tungstite occurs as powdery or earthy masses, or as thin coatings on other minerals. It exhibits a perfect cleavage in one direction.
Occurrence: This mineral is found in a variety of locations worldwide, often associated with granitic pegmatites and hydrothermal veins. Notable occurrences include the United States (California, Colorado), Russia, and several European countries.
Identification: Tungstite can be identified by its color, softness, association with other tungsten minerals, and its reaction to chemical tests. It will dissolve in hot hydrochloric acid. X-ray diffraction analysis can also be used for definitive identification.
Uses: Tungstite itself does not have significant industrial applications due to its softness and rarity. However, its presence can be an indicator of nearby economically viable tungsten deposits.
Related Minerals: Wolframite (Fe,Mn)WO4, Scheelite CaWO4, Ferberite FeWO4, Hübnerite MnWO4.