The fineness of a precious metal object (gold coin, gold bar, gold rounds, etc.), represents the weight of fine metal in it. It also includes the base metals and/or other elements within that object. In jewellery, 'base metals' are added to increase both hardness and durability to the gold product Bars are manufactured in different millesimal gold purities (or fineness), most ranging between 965 and 999.9. 999.9 Gold Bars is the Purest form of gold available for buying in Bulk.