Verdigris: Difference between revisions

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'''Verdigris''' is the common name for a green pigment obtained through the application of acetic acid to copper plates or the natural patina formed when copper, brass or bronze is weathered and exposed to air or seawater over time. It is usually a basic copper carbonate, but near the sea will be a basic copper chloride. If acetic acid is present at the time of weathering, it may consist of copper(II) acetate.
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== History ==
[[File:Statue_of_Liberty_7.jpg|thumb|right|The Statue of Liberty, covered in verdigris patina.]]
The name verdigris comes from the Middle English vertegrez, from the Old French verte grez, an alteration of vert-de-Grèce ("green of Greece"). The modern French spelling of this word is vert-de-gris ("green of grey").


== Uses ==
'''Verdigris''' is a green pigment that forms on copper, brass, and bronze surfaces due to oxidation. It is a complex mixture of copper salts, primarily copper carbonate, copper chloride, and copper acetate. Verdigris is known for its vibrant green color and has been used historically as a pigment in art and decoration.
Verdigris was the most vibrant green pigment available until the 19th century and was frequently used in the painting of manuscripts and the making of miniatures. Verdigris is lightfast in oil paint, as numerous examples of 15th-century paintings indicate. However, its use was generally avoided in the 16th century and onwards by professional painters, especially in the Netherlands and Great Britain, due to its corrosive effect on copper and lead-based pigments.


== Health effects ==
==Formation==
Ingesting verdigris can lead to [[copper poisoning]], which can cause a range of health problems from stomach pain to brain damage. It is also a skin irritant.
Verdigris forms when copper, brass, or bronze is exposed to air and moisture over time. The process begins with the oxidation of copper to form copper oxide, which then reacts with carbon dioxide and water to produce copper carbonate. In environments with acetic acid, copper acetate can also form, contributing to the characteristic green hue.


== See also ==
==Uses in Art==
[[File:Last_Supper_(by_Giotto_di_Bondone)_-_Capella_degli_Scrovegni_(Padova).jpg|thumb|left|''The Last Supper'' by Giotto, featuring verdigris.]]
Verdigris has been used as a pigment in art since antiquity. It was particularly popular during the [[Renaissance]] period, where it was used in paintings and illuminated manuscripts. Artists valued verdigris for its bright green color, although it was known to be unstable and could change color over time.
 
[[File:CrocefissioneRaffaello.jpg|thumb|right|Renaissance artwork using verdigris.]]
In paintings, verdigris was often used to depict foliage, drapery, and other elements requiring a vibrant green. However, due to its tendency to darken or fade, artists sometimes mixed it with other pigments to stabilize its color.
 
==Architectural Significance==
[[File:Spirit_of_Detroit-2560x1600.jpg|thumb|left|The Spirit of Detroit statue with verdigris patina.]]
Verdigris is also significant in architecture, where it is often seen on copper roofs and statues. The patina not only provides an aesthetic quality but also serves as a protective layer that prevents further corrosion of the metal beneath.
 
The [[Statue of Liberty]] is one of the most famous examples of verdigris in architecture. The statue's copper surface has developed a verdigris patina over time, giving it its iconic green appearance.
 
==Chemical Properties==
Verdigris is a complex compound, primarily composed of copper carbonate, copper chloride, and copper acetate. Its chemical composition can vary depending on environmental conditions, such as the presence of pollutants or acids in the atmosphere.
 
==Conservation and Restoration==
[[File:Anatoli_Boukreev_Memorial_at_Annapurna_Base_Camp.jpg|thumb|right|Verdigris on a memorial plaque.]]
Conservators face challenges when dealing with verdigris on artworks and historical objects. While the patina can be aesthetically pleasing, it can also cause damage to the underlying material if not properly managed. Conservation efforts often focus on stabilizing the verdigris and preventing further corrosion.
 
==Related Pages==
* [[Copper]]
* [[Oxidation]]
* [[Patina]]
* [[Patina]]
* [[Copper(II) acetate]]
* [[Renaissance art]]
* [[Copper poisoning]]


[[Category:Green pigments]]
[[Category:Copper compounds]]
[[Category:Corrosion]]
[[Category:Corrosion]]
 
[[Category:Pigments]]
{{stub}}
[[Category:Copper]]

Latest revision as of 11:42, 23 March 2025


The Statue of Liberty, covered in verdigris patina.

Verdigris is a green pigment that forms on copper, brass, and bronze surfaces due to oxidation. It is a complex mixture of copper salts, primarily copper carbonate, copper chloride, and copper acetate. Verdigris is known for its vibrant green color and has been used historically as a pigment in art and decoration.

Formation[edit]

Verdigris forms when copper, brass, or bronze is exposed to air and moisture over time. The process begins with the oxidation of copper to form copper oxide, which then reacts with carbon dioxide and water to produce copper carbonate. In environments with acetic acid, copper acetate can also form, contributing to the characteristic green hue.

Uses in Art[edit]

The Last Supper by Giotto, featuring verdigris.

Verdigris has been used as a pigment in art since antiquity. It was particularly popular during the Renaissance period, where it was used in paintings and illuminated manuscripts. Artists valued verdigris for its bright green color, although it was known to be unstable and could change color over time.

Renaissance artwork using verdigris.

In paintings, verdigris was often used to depict foliage, drapery, and other elements requiring a vibrant green. However, due to its tendency to darken or fade, artists sometimes mixed it with other pigments to stabilize its color.

Architectural Significance[edit]

The Spirit of Detroit statue with verdigris patina.

Verdigris is also significant in architecture, where it is often seen on copper roofs and statues. The patina not only provides an aesthetic quality but also serves as a protective layer that prevents further corrosion of the metal beneath.

The Statue of Liberty is one of the most famous examples of verdigris in architecture. The statue's copper surface has developed a verdigris patina over time, giving it its iconic green appearance.

Chemical Properties[edit]

Verdigris is a complex compound, primarily composed of copper carbonate, copper chloride, and copper acetate. Its chemical composition can vary depending on environmental conditions, such as the presence of pollutants or acids in the atmosphere.

Conservation and Restoration[edit]

Verdigris on a memorial plaque.

Conservators face challenges when dealing with verdigris on artworks and historical objects. While the patina can be aesthetically pleasing, it can also cause damage to the underlying material if not properly managed. Conservation efforts often focus on stabilizing the verdigris and preventing further corrosion.

Related Pages[edit]