Bronze

Bronze is an alloy made of copper and another metal, usually tin. Compositions vary, but most modern bronze is 88% copper and 12% tin.

Although at one time bronze was any alloy consisting of copper with tin and brass was an alloy of copper with zinc, modern usage has blurred the lines between brass and bronze. Now, copper alloys generally are called brass, with bronze sometimes considered a type of brass.

Bronze usually is a golden hard, brittle metal. The properties depend on the specific composition of the alloy as well as how it has been processed.

From  http://chemistry.about.com/od/alloys/f/What-Is-Bronze.htm