Description

Pure germanium is a hard, lustrous, gray-white, brittle metalloid. It has a diamond like crystalline structure and it is similar in chemical and physical properties to silicon. Germanium is stable in air and water, and is unaffected by alkalis and acids, except nitric acid.

Germanium is less abundant than either tin or lead, which is the heavier component metals of group *4, and it is less easily accessed because geological processes have contracted only small amounts of it into minerals, so that it tends to be widely dispersed. Germanium ores are rare. The least rare, germinate, is a copper-iron-germanium sulfide with 8% of the element, but even this is not mined. Germanium is widely distributed in ores of other metals, such as zinc, and that which is required for manufacturing purposes is recovered as a by-product from the flue-dusts of zinc smelters. World production is about *0 tons per year.

Germanium is an important semiconductor, mainly used in transistors and integrated circuits. They are often made from germanium to which small amounts of arsenic, gallium, or other metals. Germanium forms many compounds. Germanium oxide is added to glass to increase the index of refraction; such glass is used in wide-angle lenses and in infrared devices. Numerous alloys containing germanium have been prepared. High purity germanium single crystal detectors can precisely identify radiation sources (e.g. for airport security).