How does gold rust ?

gold does not rust easily the only way to do it is electrolysis using gold as the positive electrode and that might not even work you made need to add a nitrate to even affect it but Ive never done it

Pure Gold will not rust under any condition. Pure Gold is 99.999 pure. Anytime someone sees Gold rust is when it is mixed with other metals, and again, it's not that Gold that rust

Rusting is oxidation. Gold oxides are very difficult to make. It can be dissolved in aqua regia (HNO3 + HCl) but I don't know of a method of precipitating gold oxide from the solution. I thought it could only be oxidized under elevated pressure with a very strong oxidizing agent like perchloric acid.

However, there is an old (1890) method to precipitate gold oxide at ambient pressure but it is very complicated and involves aqua regia, potassium cyanide solution, ammonia, and MgO -- not the sort of think likely to happen by chance. Reference below (p. 638)

Gold is very unreactive. It may not rust but it will acquire what is called a "patina." Any metal that oxidizes may be said to rust. If your gold rusts green, it's not (the) gold. Either it's not gold or it is an amalgam with a metal that does rust.

Gold does not rust! If it does then it is not real!