Main Page | See live article | Alphabetical index Copper carbonate is a blue-green compound forming most of the patina one sees on weathered brass, bronze, and copper. The color can vary from bright blue to green, because there may be a mixture of both copper carbonate and basic copper carbonate in various stages of hydration. It was formerly much used as a pigment, and is still in use for artist's colours. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.