Investment coins - also called bullion coins - are coins minted for the precise purpose of the investment and are not used as a means of payment. Although they have a face value and may be accepted as a means of payment, they are not normally used as such. Investment bullion coins, minted as Brilliant Uncirculated (BU), are regularly in circulation in the investment market. Their minting quality and availability in circulation differ from collector coins, which also bring an emotional value for numismatics enthusiasts, are characterized by a superior minting quality (e.g. 'proof' ) and remain part of a collection for a long time, before seeing a large increase in their value.