The Statue of Liberty gets its green color from the patina formed on its copper surface

Patinas are chemical compounds formed on the surface of metals. There is a wide range of chemicals both household and commercial that can give a variety of results. They are often used by artists as surface embellishments either for color, texture, or both. One example of a patina is a green surface texture created by slow chemical alteration of copper, so as to produce a basic carbonate. It can form on pure copper objects as well as alloys which contain copper, such as bronze. Many patinas form naturally, by weathering. Statue of Liberty File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Statue of Liberty File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Jump to: navigation, search General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ... The common (Arrhenius) definition of a base is a chemical compound that either donates hydroxide ions or absorbs hydrogen ions when dissolved in water. ... Jump to: navigation, search An alloy is a combination, either in solution or compound, of two or more elements, which has a combination of at least two metals, and where the resultant material has metallic properties. ... Bronze figurine, found at Öland Bronze is the traditional name for a broad range of alloys of copper. ...

A bronze coin of the Han Dynasty - circa 1st century BC with green patina.

Patinas are restricted to exposed surfaces and can flake off. One reason that bronze is so highly valued in statuary is that its patina protects it against further corrosion. This natural patina seldom shows a tendency to flake. Brass would also be resistant to corrosion, but it would in the long run not be as attractive, as local pitting would show against a shiny background. Jump to: navigation, search ImageMetadata File history File links Hancoin1large. ... Jump to: navigation, search ImageMetadata File history File links Hancoin1large. ... Jump to: navigation, search Han commanderies and kingdoms AD 2. ...

Figuratively, "patina" can refer to any fading, darkening or other signs of age, which are felt to be natural and/or unavoidable.

The chemical process by which a patina forms is called "patination," and a work of art coated by a patina is said to be "patinated."

"patina" is also found on sliprings and commutators. This type of "patina" is formed by; corrosion, what elements the air might hold, ressidue from the wear of the carbone brush, moisture, and need special condotions to work as intended.