As with other related rare-earth metals, gadolinium is silvery white, has a metallic luster, and is malleable and ductile. At room temperature, gadolinium crystallizes in the hexagonal, close-packed alpha form.
The metal is relatively stable in dry air, but tarnishes in moist air and forms a loosely adhering oxide film which falls off and exposes more surface to oxidation.
Melting point: 1313 °C Boiling point: 3273 °C
A foil is a thin sheet of pure metal. Given its fragile nature, some foils have protective coatings.