Rare earth metals comprise 17 chemical elements in the periodic table, which include
fifteen elements of the lanthanide series, and scandium and yttrium. Scandium and
yttrium are also considered rare earth metals as they are found in the same mineral
ore deposits as the other elements of the lanthanide series. Rare earth metals have
unique physical and chemical properties, which make them suitable to alloy with other
metals in applications that require properties such as enhanced magnetic strength and
high-temperature resistance.