Niobium…
Niobium, which was formerly columbium, is a chemical element with the symbol Nb (formerly Cb) and atomic number 41.
Niobium has a similar structure to Tantalum and is produced in a similar method.
It too has a very high melting point of around 2470°C.
It has excellent corrosive resistance and has good cold ductility.
It is however half as dense as Tantalum.
Applications include; sintering trays and boats, special chemical applications, superconductors, medical components, jet engine parts and is used in the lighting industry.