Carat Weight

This is a unit of weight for diamonds and other gemstones. The carat formerly varied somewhat in different countries, but the metric carat of 0.200 grams or 200 milligrams,was adopted in the United States in 1913 and is now standardised in the principal countries of the world. It is sometimes incorrectly spelled "karat", but in the USA this term only refers to the fineness of pure gold and gold alloys