A silvery-white semi-metal. It is brittle.Germanium is a semiconductor. The pure element was commonly doped with arsenic, gallium or other elements and used as a transistor in thousands of electronic applications. Today, however, other semiconductors have replaced it.Germanium oxide has a high index of refraction and dispersion. This makes it suitable for use in wide-angle camera lenses and objective lenses for microscopes. This is now the major use for this element.Germanium is also used as an alloying agent (adding 1% germanium to silver stops it from tarnishing), in fluorescent lamps and as a catalyst.Both germanium and germanium oxide are transparent to infrared radiation and so are used in infrared spectroscopes.