32; Atomic Weight 72.59; Density 5.323 g/ccm;
Mendelejeff predicted the existence of germanium in 1871, calling it “eka-silicon”. Winkler discovered it at Freiberg, Saxony, in 1886, naming it after his native country. Germanium is only found in very rare minerals such as argyrodite, a silver mineral from Freiberg and Bolivia, as well as germanite, a copper-iron-germanium-sulfide only occuring in Tsumeb, Namibia.
Today Germanium is produced on an industrial scale from intermediate products of zinc and copper smelting and coal burning. Germanium is a brittle, silvery-shining semimetal. It is the classical semiconductor used by Shockley for the basic work on the properties of semiconductors which paved the way for developing transistors. Germanium has now largely been superseded by silicon in its classical field of application, the production of semiconductor components. Its transparency for infrared light combined with a very high refractive index of about 4 makes it the preferred material for infrared optics.
is a very important catalyst for the production of high quality polyester,
germanium tetrachloride being essential in the manufacture of fibre optic
cables used for telecommunications.