Hydrolysis of the higher oxidation state fluorides and chlorides gives oxide halides and these compounds may also be prepared directly from oxides and halogenating agents. 2- are known and their chemistry is similar to that of the halides. Scheele and Berman suggested the possibility of obtaining a new metal by reducing this acid. Tungsten occurs in wolframite, scheelite, huebnertie, and ferberite. Important deposits of tungsten occur in California, Colorado, South Korea, bolivia, Russia, and Portugal.
Natural tungsten contains five stable isotopes.
Twenty one other unstable isotopes are recognized. The metal is obtained commercially be recucing tungsten oxide with hydrogen or carbon. Very pure tungsten can be cut with a hacksaw, and can be forged, spun, drawn, and extruded. The impure metal is brittle and can be worked only with difficulty. Tungsten has the highest melting point of all metals, and at temperatures over 1650C has the highest tensile strength.