Hafnium is a ductile metal with a brilliant silver luster. Its properties are considerably influenced by presence of zirconium impurities. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Although their chemistry is almost identical, the density of zirconium is about half of hafnium. Very pure hafnium has been produced, with zirconium being the major impurity.
Melting point: 2233 °C Boiling point: 4603 °C
A foil is a thin sheet of pure metal. Given its fragile nature, some foils have protective coatings.