Sample of the element niobium Nb rotating. Niobium has the atomic number 41, and is a soft, ductile transition metal. It is used in specialist steels and other alloys, in superconductors and in jewellery. It is found in several minerals including columbite niobite, pyrochlore and samarskite. It was originally called columbium and this name still persists in the names of some alloys such as columbium steel.