The Statue of Liberty is made of copper and has a framework of steel. The copper is 3/32 in. (2.4 millimeters) thick, which is the same as two U.S. pennies put together. The statues copper has naturally oxidized over time to form its familiar "patina" green coating, which is as thick, in many places, as the copper behind it and is protecting the copper from naturally wearing away. The statues metal framework was built by Gustave Eiffel. The statue stands 305 feet tall and used 31 tons of copper and 125 tons of steel.