Campanology Word of the Day: Verdigris

“Give me your tired, your poor, your huddled masses yearning to breathe free.” These stirring words likely conjure for you an image of a draped figure, rising from the Hudson with torch held aloft, her aspect washed in a greenish, eggy blue. However, you may be surprised to know the Statue of Liberty wasn’t always this color. 

A gift from the people of France to the people of the United States, the Statue of Liberty arrived on our shores a brilliant reddish copper. Over more than a century, her surface darkened to a warm earth tone that gradually became the iconic weathered shade we see today: verdigris.

Verdigris is the green or bluish patina formed on copper surfaces when exposed to oxygen. It is the result of a chemical reaction between the base metal copper and surrounding elements.

Alloys with copper as a significant component, like brass (roughly 2-1 parts copper to zinc) or bronze (roughly 4-1 parts copper to tin), may also form verdigris. In bronze bells, the tin within the alloy lends a softer, glaucous overtone, and imparts more grey into the patina.

Unlike other types of corrosion, say, rust on iron or tarnish on silver, verdigris can be beneficial to the host metal. Verdigris forms a thin but protective layer across the metallic surface – shielding the unreacted metal underneath from further degradation. It’s oxidation that prevents more oxidation. 

Continuing with the Statue of Liberty as an example: after over a century of exposure to the elements, verdigris is evenly dispersed over the entire surface in a layer roughly the depth of two sheets of paper. This thin layer of verdigris seals the original copper below from further decay.

Green of Greece

The word verdigris entered the lexicon in the 14th century, coming from the Middle English vertegrez, which itself was pulled from the Old French verte grez, an alteration of vert-de-Grèce. This “green of Greece” was a pigment emblematic of the Greek islands at the time, the paintings and bronze objects of which were highly valued. The modern French spelling of the word is vert-de-gris, or “green of grey.”

Bells in Greece with Verdigris

Image: Two bells suspended from a tower in Santorini, Greece, displaying a surface of blue-green verdigris.

For centuries, verdigris was the most brilliant green readily available to painters. While it would happen naturally to bronze objects in nature, artists would manufacture the chemical reaction, mix it with binding agents, and then apply the blue-green hue to canvas. Masterpieces by Jan van Eyck, Raphael, and El Greco provide examples of verdigris in use during the Middle Ages and early Renaissance. 

It’s hard to define verdigris as a color. Blue-green, yes. Turquoise, perhaps. Robin’s egg, almost. Verdigris is not one precise shade. Rather, it’s an active, evolving state – a color made from change. Crystalline in nature, you look into verdigris, not at it. Perhaps that’s why it adds such depth of interest to a bell, which has no flat surface. The color invites you in and beckons you to look and listen to beauty.