Samarium is a metallic element with the chemical symbol Sm and atomic number 62. This is a medium hardness silver white metal that is prone to oxidation in air. As a typical component of the lanthanide element series, samarium typically assumes an oxidation state of+3. The most common compounds of samarium (II) are SmO, SmS, SmSe, and SmTe. Samarium has no significant biological effects, only mild toxicity.