carat (gold purity), carat (mass) قيراط qīrāt, a small unit of weight, defined as one-twentyfourth (1/24) of the weight of a certain coin namely the medieval Arabic gold dinar, and alternatively defined by reference to a weight of (e.g.) 3 barley seeds. In medieval Arabic the word was also used with the meaning of 1/24th of the money value of a gold dinar coin. In the Western languages the word was adopted as a measurement term for the proportion of gold in a gold alloy, especially in a gold coin, beginning in Italy in the mid-13th century, occurring soon after some city-states of Italy started new issues of pure gold coins.[8]