Samarium is a rare earth element that is found in small amounts in the Earth's crust. It is a silvery-white metal that is relatively soft and malleable. Samarium has a variety of uses, including in nuclear reactors, magnets, and lasers
From Wikipedia
Samarium is a chemical element; it has symbol Sm and atomic number 62. It is a moderately hard silvery metal that slowly oxidizes in air. Being a typical member of the lanthanide series, samarium usually has the oxidation state +3. Compounds of samarium(II) are also known, most notably the monoxide SmO, monochalcogenides SmS, SmSe and SmTe, as well as samarium(II) iodide.