Niobium is a shiny, white, soft, and ductile metal, and takes on a bluish cast when exposed to air at room temperatures for a long time. The metal starts to oxidize in air at 200°C, and when processed at even moderate temperatures must be placed in a protective atmosphere.
Melting point: 2477 °C Boiling point: 4744 °C
A foil is a thin sheet of pure metal. Given its fragile nature, some foils have protective coatings.