Copper is the natural resource that comes to mind when people think about the Statue of Liberty. The statue’s “skin” is made from copper like that of a United States penny. Copper is strong, lightweight and easily shaped – ideal characteristics for a 305 foot 1 inch statue. The copper surface is 3/32 of an inch (2.37mm) thick -- the thickness of two pennies put together. In other words the statue is quite thin.
The appearance of the statue has changed over the years from brown when it was erected to the green it is today due her exposure to air and water. Over time the copper reacts, forming a layer of patina. This natural reaction is why the statue is green.
Even though the statue is thin, it took a lot of copper to make a 305 foot 1 inch statue, 62,000 pounds (28.12 metric tons) to be exact. Where did all that copper come from? A 1985 analysis revealed a match to the copper from the Vigsnes mine off the coast of Norway. On the outer walkway of Liberty Island you can see a 500 pound (.23 metric ton) rock. This is a piece of copper ore from the mine that was donated by the Norwegian government to tell the story of the Statue’s best known natural resource.