Germanium, chemical element, symbol Ge; for physical constants see Periodic Table. Germanium was discovered in 1886 by Clemens Winkler. It occurs in the mineral germanite, in zinc ores, and in coal. It is produced by reducing its dioxide with hydrogen. Germanium is a crystalline, brittle metalloid. It is used extensively in semiconductors. Germanium and its compounds are used in transistors, alloys, and phosphors and as catalysts.