Bullion traditionally stands for gold bars, silver bars, other precious metals bars or ingots. The word bullion comes from the old French word bouillon, which meant “boiling” and was the term for a mint or melting house. In recent years, the term bullion has also been used to describe ingots or bars of base metals such as copper, nickel, or aluminium. It also get used to refer to a metal piece shaped in the form of a coin or a bar and plated with a precious metal. Examples are gold plated bars and coins sold on ebay.