Sg, or Sg, is the chemical symbol for the element samarium, which is a rare earth metal. It is part of the lanthanide series and is known for its silvery-white appearance. Samarium is used in various applications, including magnets, lasers, and nuclear reactors due to its unique properties. In nature, samarium is typically found in minerals such as monazite and bastnäsite. It was discovered in 1853 by the French chemist Paul Émile Lecoq de Boisbaudran. Samarium has several isotopes, with samarium-152 being the most stable and abundant, making it useful in scientific research and industrial applications.