scandium, Metallic chemical element, one of the transition elements, chemical symbol Sc, atomic number 21. It was discovered in 1879, and its name derives from the Latin term for Scandinavia. Scandium is a silvery white, rather soft metal and is produced mostly as a by-product of uranium extraction from the mineral davidite, which contains about 0.02 percent scandium oxide. Very few uses of this unusual metal have been developed.