Tungstates and Molybdates

Tungstates and Molybdates

Characterized by its square tabular crystals, orange to yellow color, high luster and association with other lead minerals, wulfenite is found in the oxidized zones of hydrothermal lead deposits. Discovered in 1845, it is named after the Austrian Jesuit mineralogist, Franz Xavier von Wulfen (1728-1805).

Its dark color, one direction of perfect cleavage, and high specific gravity distinguish this mineral from others. It is a comparatively rare mineral found usually in pegmatites and high temperature quartz veins. It is a chief ore of tungsten, which is used as a hardening metal in the manufacture of high-speed tools such as carbides.

An ore of tungsten, this mineral was named after Karl Wilhelm Scheele (1742-1786), Swedish chemist, who proved the existence of tungsten oxide in the mineral in 1781. It is found in granite pegmatites, contact metamorphic deposits, and high temperature hydrothermal veins

The minerals that make up this class are composed of either tungsten or molybdenum or a mixture of both in combination with a metal.

Tungstates are very important industrial minerals yielding tungsten metal, which when alloyed with iron, produces strong corrosion-resistant steel. The metal is also used extensively in the manufacture of filaments for light-bulbs and vacuum tubes. Molybdates are also important ores that are used as an alloy in stainless steel to make it stronger and more highly resistant to heat.