The formation of green colour is due to corrosion. During monsoon, copper metal, upon exposure to the atmosphere forms a mixture of hydroxide and carbonate of copper. ... The surface of copper metal is coated with a green layer, which contains hydroxide and carbonate of copper.

Why do copper vessels develop a greenish layer?

When a copper statue (or copper vessel) is exposed to moist air for long, it acquires a dull green coating. The green material is a mixture of copper hydroxide [Cu(OH)2] and copper carbonate (CuC03) formed due to the reaction of copper with moist air.

What is the green stuff on copper?

Causes of Patina

Oxidation is common on copper when it is exposed to water and air over time. While this oxidized layer is not harmful, it does cause the copper to become corroded. This green colour is known as copper oxide and is basically a rusting of the metal.