Uranium in its normal state is a naturally occurring radioactive metal. It is a heavy metal with a silvery-white color and a slightly bluish cast when viewed in bulk. Uranium is relatively soft and malleable, with a Mohs hardness of 5.5. It has a high melting point of 1,132°C (2,070°F) and a boiling point of 3,818°C (6,904°F). Uranium is the densest naturally occurring element, with a density of 19.1 grams per cubic centimeter (g/cm³).