Karats (denoted as KT) and Fineness Number are two ways to determine the purity of gold. The carat value of gold jewellery is typically measured in three numbers and varies from 14k to 22k. e.g. A 22k gold ring has a purity grade of 916 HallMark. It denotes purity of 916 parts per 1000 or 91.6 percent. Similarly, 18k and 14k gold jewellery have purity grades of 750 and 585, respectively.