Tungsten (W) also called wolfram is a shiny white metal and in its purest form, is quite pliant and easily processed. However, small amounts of oxygen or carbon increase its hardness and brittleness. Tungsten has many physical and chemical characteristics – it has the highest melting point of all elements except carbon, is on of the heaviest metals and has an extremely high conductivity (28% greater than that of silver). Based on these properties, tungsten is used as an alloy in hardening steel and the manufacture of “hardmetal”, whose main constituent is tungsten monocarbide which has a hardness close to that of diamond. Tungsten is also used extensively in tungsten metal products in lighting filaments, electronic contacts, wire and rods. Tungsten is also used in the chemical industry in the form of catalysts.

There are more than twenty tungsten bearing minerals, with only two being important economically, namely wolframite (Fe, Mn)WO4 and scheelite CaWO4. Economic grades of tungsten vary between 0.3 and 1% WO3. China, CIS and Austria are the world’s major producers of tungsten.