Niobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41.
N 6377 (OTTO) Niobium powder, 625 mesh (12 mic aps), 99.9% Cas no 7440-03-1 - used in various superconducting materials, applications of niobium include welding, nuclear industries, electronics, optics, numismatic.