Erbium is a rare earth metal that was discovered in 1842 by Carl Gustaf Mosander. It has a melting point of 1802 K and a boiling point of 3141 K. Erbium is malleable and soft yet stable in air, though it does not oxidize as quickly as some other rare earth metals. Its salts are rose-colored and it has characteristic absorption spectra bands in visible light, ultraviolet, and near infrared.