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.
