Unit for measuring the content of gold alloys. The pure gold content of an alloy of 1 carat is 1/24th of the weight of the alloy. An alloy of 12 and 18 carats contains 12/24ths and 18/24ths of gold respectively. Pure gold is therefore 24 carats. A carat is also the unit of weight for precious stones, equal to 0.200g.
