Germanium was discovered in 1886 by the German chemist Clemens Winkler, who isolated it from the mineral argyrodite. He named it after his homeland, Germany (Latin Germania). Germanium is a hard, greyish, brittle metalloid whose semiconducting properties made it the material of the first transistors in the late 1940s, before silicon largely displaced it; it remains important in fibre optics and infrared optics.
The semiconductor of the first transistors, germanium now serves chiefly in fibre-optic cable, in the infrared lenses of night-vision and thermal-imaging equipment, and as a catalyst, and it is recovered largely as a by-product of zinc refining. The first working transistor, built at Bell Labs in December 1947 by John Bardeen, Walter Brattain and William Shockley, used a germanium crystal, and the trio shared the 1956 Nobel Prize in Physics for the invention that founded modern electronics, before silicon's cheaper abundance and better high-temperature performance displaced germanium through the 1950s and 60s. The element later acquired an unrelated and discredited reputation in alternative medicine: organogermanium compounds were marketed from the 1970s, especially in Japan, as an energy-boosting health supplement, until case reports of serious kidney damage and several deaths led health authorities to warn against the products.