Neodymium
Neodymium is a chemical element with the symbol Nd and atomic number 60. It is a soft silvery metal which tarnishes in air. Neodymium was discovered in 1885. It is present in significant quantities in the ore minerals monazite and bastnäsite. Neodymium is not found naturally in metallic form or unaccompanied by other lanthanides and it is usually refined for general use.
Neodymium, a rare earth metal, was present in classical mischmetal to the extent of about 18%. The metal has a bright, silvery metallic luster; however, as one of the more reactive rare earth (lanthanide) metals, it quickly oxidizes in air. The oxide layer then falls off, which exposes the metal to further oxidation. Thus a centimeter-sized Nd sample completely oxidizes within a year.
Neodymium exists in two allotropic forms, with a transformation from a double hexagonal to a body-centered cubic structure taking place at 863 °C
