What are the Causes for Copper to Turn Green?
Posted by Hellas on
August 27, 2009
Copper reacts when oxygen in the air on moderate temperature and format a light color brownish black coating on the surface.
Generally air or oxygen have chemical reaction on copper oxide and gradually turn it into green.
Significantly unlike iron that start getting rusty when it has oxidization, when copper has this process over the green layer actually saves the metal from further deterioration. Often you can see a visible layer of green on the gold coated roofs which is called copper carbonate or verdigris.
The most popular example of this chemical reaction is Statue of Liberty.