Samarium is a lustrous silver-white metal.
It is one of the rare-earth metals of the lanthanide series in group IIIb of the periodic table . Naturally occurring samarium is a mixture of seven isotopes, three of which are radioactive with extremely long half-lives. The metal was not isolated in relatively pure form until recently, although it has long been used in pyrophoric alloys used in cigarette lighter flints. Samarium is used as a catalyst in certain organic reactions. The oxide, samaria, is used in special infrared absorbing glass and cores of carbon arc-lamp electrodes.