Zirconium is a lustrous, greyish-white metal that is solid at room temperature but becomes hard and brittle at lower purities. It is soft, ductile, and malleable, with a melting point of 2128 K and boiling point of 4682 K. Zirconium is highly resistant to corrosion by many chemicals but will dissolve in hydrochloric and sulfuric acid, especially with fluorine present.