Niobium / Columbium
| Symbol: | Nb (Cb) |
| Number: | 41 |
| Melting point: | 2.477 °C |
| Density: | 8,57 g/cm³ |
| Appearance: | gray metallic |
| Characteristics: | rare, soft, grey, ductile transition metal |
| Occurrence: | Brazil, Canada, Nigeria, DR Congo, Russia |
| Applications: | Stainless steel As an alloying addition to increase resistance to corrosion Nickel based special alloys and super alloys |
| Size: | Ferro-Niobium as alloying addition for steels and stainless steels Nickel-Niobium in superalloys to improve temperature-stability |