Although organised refiners adopt standard purities of 995 or 999, most of the coins sold are 916.6 (22 Karat). The purity can also be specified by the retailer or corporate entity ordering the coins (e.g. 23 Karat, 21 Karat, 20 Karat and 18 Karat). For gold coin investment purposes most of the coins bought are either 22 karat or 24 karat.