Verdigris: is a bright blue-green patina, or natural “coating”, that is formed when copper, bronze or brass is exposed to air or seawater over a period of time. The Statue of Liberty is an excellent example of this. The term is a variation on the Old French “vert-de-Grèce”, meaning “green of Greece”; however the contemporary French spelling “vert-de-gris” translates to “green of grey”. Until the 19th century Verdigris was also a sought after green colour pigment often used in paintings.
The Design Tabloid 