Why would metal have any smell at all? Are particles of copper released into the air?
Coins harbour all sorts of bacteria, and are responsible for the transmission of a great deal of disease. Copper atoms cannot evaporate to any great extent. You are probably smelling the effects of people handling the coin for years!
Pure copper has no smell that people can detect because there is virtually no significant vapor pressure of copper atoms at room temp. Pure copper will react quickly with things like sulfur and hydrogen. The copper sulfide on the surface has a vapor pressure and will leave a metallic taste when inhalled.
