One often speaks of a ring as being 14-carat gold, or of 22- or 18-carat watch cases or jewelry, but do all of us know just what we mean by 14, 18 or 22 carat?

Gold is divided into twenty-four parts - that is, pure gold is said to contain twenty-four carats - the carat being just a measurement term. A ring or watch case marked 14K or 18K means that fourteen or eighteen parts of it are pure gold, the balance of the twenty-four carats being some sort of alloy, copper being generally used. If articles of jewelry were made of pure gold they would not wear well, as gold is a very soft metal, and it is, therefore, necessary to mix the gold with some harder substance.