Erbium

Erbium, chemical element, symbol Er; for physical constants see Periodic Table. Erbium was discovered in 1843 by Carl G. Mosander. It occurs in the minerals xenotime, gadolinite, euxenite, fergusonite, and is obtained commercially from monazite. It is prepared by reducing anhydrous chloride with calcium metal. Erbium is a silvery, soft, reactive metal, belonging to the series of elements known as the rare-earth metals. Ion-exchange and solvent extraction techniques have led to much easier isolation of the rare-earth elements. Erbium and its compounds are used in carbon-arc lighting applications, special glasses and enamels, and refractory materials.