Oxidised copper turned the Statue of Liberty green

Believe it or not, when New York’s Statue of Liberty was unveiled in 1886, it was a dull brown colour. Comprised of more than 80 tonnes of copper, the statue began to turn green due to the oxidation of its copper plating (when copper is exposed to water and air it loses electrons and consequently turns green).

By 1920, the transition to green was complete, 34 years after the statue was unveiled. It’s not necessarily a bad thing though — this thin layer of oxidation protects the statue from the elements, and we know it is capable of preserving metal for centuries, as shown by artifacts from the ancient world. Another perk of this oxidation effect: you can enlist it to detect cheap jewellery. If your ring turns your finger green, chances are it contains more copper than gold.

Copper is naturally antibacterial

Alesser-known fact about copper is that it is a natural antibacterial agent. When bacteria, fungi or viruses land on a copper surface, electrically charged ion particles inflict damage on a microbe’s cell membrane or its viral coat, which destroys the RNA or NDA inside an organism. This reaction prevents harmful microbe from mutating or developing a resistance against the antimicrobial properties of copper.

This discovery has led to copper being a popular choice for doorknobs, handrails and fingerplates in public buildings to prevent the spread of bacteria. It is also widely used in the medical industry to reduce infection. Copper is even woven into fabrics to make anti-microbial garments such as socks that combat foot fungus.

Published in Dawn, Young World, March 22nd, 2025