Question: what is difference between copper and gunmetal?
Answer: is that copper is (uncountable) a reddish-brown, malleable, ductile metallic element with high electrical and thermal conductivity, symbol cu, and atomic number 29 or copper can be (slang|law enforcement) a policeman while gunmetal is an alloy of 88% copper, 10% tin and 2% zinc, originally used for making guns.