Q1479When it was unveiled in 1886, the Statue of Liberty was the warm brown of new copper; the famous green is a patina that slowly formed as the metal reacted with the air over about thirty years.
Its copper skin is only about two millimetres thick — roughly two coins — yet the thin green crust that grew over it actually protects the metal beneath from further corrosion. When a plan was floated to repaint it during a 1980s restoration, the public objected: the colour we now think of as the statue is really the mark of time working on it.

