Ceratonia siliqua harubh. "Ceratonia siliqua", the scientific name of the carob tree, derives from the Greek "kerátiοn" κεράτιον 'fruit of the carob (from "keras" κέρας 'horn'), and Latin "siliqua" 'pod, carob'. The unit "carat", used for weighing precious metal and stones, also comes from κεράτιον, as alluding to an ancient practice of weighing gold and gemstones against the seeds of the carob tree by people in the Middle East. The system was eventually standardized, and one carat was fixed at 0.2 grams. In late Roman times, the pure gold coin known as the "solidus" weighed 24 carat seeds (about 4.5 grams). As
Carat (mass) Carat (mass) The carat (ct) (not to be confused with the karat, sometimes spelled carat, a unit of purity of gold alloys), is a unit of mass equal to 200 mg (0.2 g; 0.007055 oz) and is used for measuring gemstones and pearls. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in many countries around the world. The carat is divisible into one hundred "points" of two milligrams each. Other subdivisions, and slightly different mass values, have been used in the past in