Clarke is a unit of weight for precious stones. One carat world unity is 200 mg, 1 / 5 grams. Carat this noun, is Greek, meaning is a kind of locust growth Mediterranean fruit. The fruit by the same weight, therefore, in ancient times was used as a unit of weight for precious stones. In the past, Clarke the weight is not uniform, some countries with 210 mg for one carat, some with 180 mg for one carat.1877 English, law, the Netherlands and other countries agreed to 205 mg for one carat, by 1907, with the standard metric, metric meeting in Paris was finally revised to 200 mg.
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