There are a number of refiners worldwide who produce the rock in bars. Genuine bars have been engraved with the seal of the respective refiners. Dealers use the seal to identify the rock. All major brands have been accepted as a commodity that can be used in trade provided they are accredited a certain Bullion Market Association.
There are various ways of investing in this commodity. Though the simplest way of engaging in this business is through buying bullion, this is not an option that every investor would consider ideal. Many other investors prefer to buy financial instruments based on the precious metal.