The Statue of Liberty, inaugurated in 1886, was originally a bright copper color, not the familiar green silhouette it is today. It took about twenty years for the characteristic green patina to fully cover its 80 tons of copper. According to the National Park Service (NPS), this transformation was complete in 1906. The statue's first coat had the brilliance of a freshly struck coin. The Statue of Liberty was constructed in France and completed in 1884 before being dedicated in New York in October 1886. During these early years, sailors entering the harbor saw an orange-red giant, not the green lady of postcards. The NPS notes that the statue is composed of 176,000 pounds of copper, or about 80 tons, with each leaf being approximately 3/32 of an inch thick, or about 2.4 millimeters. This thickness is comparable to two one-cent coins stacked. The metal is stretched over a framework that supports the entire structure. New copper does not stay new for long. Upon contact with oxygen, its surface first forms a pinkish red mineral, cuprite, then a black layer, tenorite, which darkens the statue. Sulfur dioxide from the atmosphere gives rise to the blue-green mineral, brochantite, and the salt spray from the harbor, whose chloride ions produce the olive-green atacamite. The American Chemical Society summarizes the recipe for a patina "in twenty years." According to History.com, the statue passed through a period of fifteen years from bright copper to a dark, dull shade. The greening then appears: the press mentions it as early as 1902, and the patina is complete in 1906. This phenomenon is not exotic; the same reaction colors forgotten coins at the bottom of a drawer or the copper roofs of old buildings. In New York, the setting changes everything: salt from the harbor, air heavy with sulfur, and an immense copper surface exposed to the wind. In 1906, the same year the green finished, painting almost won. According to several accounts, including that of the Copper Development Association, Congress would have allocated funds to cover the statue with paint. The idea was based on a widespread certainty: this green could only be corrosion, a sign of a monument in decline. The legislators thought they were saving the copper, while they were about to cover its best protection. Public reaction was not long in coming. According to the American Copper Association, a newspaper of the time called the project "a sacrilege." Historian Daniel Wortel-London notes in an interview with History.com that a layer of paint would have needed to be reapplied approximately every 25 years to maintain its freshness. He adds that as New Yorkers grew up with a green statue, restoring the old color lost its meaning. Army engineers would have been consulted and judged the patina to be harmless to the structure. Only the interior of the statue would have finally received paint, according to some accounts. Faced with protests, the project was abandoned. This patina is not the rust of copper. It forms a stable layer that isolates the healthy metal underneath, so well that the color considered suspicious in 1906 actually protects the statue. According to the American Chemical Society, it continues to prevent new chemical reactions on the copper it covers. Approaching the centenary, more than 500 skilled workers cleaned the copper under a scaffold covering the entire building, without removing the patina. Inside, the old coverings, estimated at about ten layers, were stripped with liquid nitrogen and then with sodium bicarbonate. The current torch, installed in 1986, is copper covered with 24-karat gold leaf, which reflects the sun during the day. The original is displayed since 2018 in the Torch Gallery of the Statue of Liberty Museum.