14k is 14 parts gold and 10 parts other metals. Based on 1976 information, 10k is the legal minimum accepted standard of gold karatage in the USA, with 14k being the most popular. In France and Italy, 18k is the lowest permissible standard to be called gold. England accepts 9k gold, while in some countries of the world, 8k is the legal minimum standard. Gold can be alloyed in a range of colors but only a few alloys have the right combination of strength, beauty and workability to qualify for use in jewelry.
Most jewelry contains a mixture of at least two other metals.
Green gold is achieved when silver, and sometimes small amounts of copper and zinc are used as alloys. A pink or red tint results when gold is alloyed with copper. White gold is made by combining gold with copper, nickel and zinc. Small amounts of alloy metals can make a noticeable difference in the color of these coins. The pure gold is noticeably yellow in comparison.