Patina
Definition
A thin film, usually green or blue in color, that forms over time on certain metals (such as copper, brass, bronze, and aluminum) or wood and stone surfaces due to natural oxidation.Things you need to know
On metals, patina is caused by carbonates, oxides, sulfides, and/or sulfates. If you dislike the look of patina, avoid using metals that are prone to developing it.
Also known as
Verdigris
