Verdigris is the blue-green tarnish on certain metals after they are left outside for a long period of time. A lot of churches have rooftops coated with verdigris, and many capitol buildings have verdigris on their domes.
Bronze, brass, and copper metals get verdigris because of exposure to air and wetness, especially saltwater. The Old French origin of verdigris literally translates to “green of Greece,” which can help you remember how to pronounce the word: VURR-de-Greece. The word is a noun that refers to the actual layer of green pigment that coats a surface. It’s a handsome color, and many painters use verdigris when they want a sea-foam look.