CARAT

Carat is the unit used to indicate the fineness of gold (Karat – K). It is also a unit of weight for gemstones (Carat – ct.).

1. Symbol: K. Unit of gold fineness (24K = pure gold, 18K = 750/1000, etc.)
2. Symbol: ct. Unit of weight used for gemstones. 1 ct equals 0.200 grams. The origin of this unit lies in the carob seed, whose weight is remarkably consistent. Carob seeds were historically used to weigh precious stones.

Useful link:

– Gold
– Materials of mineral origin