Rare earth magnets are made out of the rare earth of elements in the periodic table and are famous for their strength. The most common are neodymium-iron-boron (NdFeB) and samarium cobalt (SmCo) varieties. Despite the name, rare earth elements are relatively abundant in the earth's cust, however, they are not typically found in economically exploitable deposits and are often dispersed, deriving the term 'rare earth'.