carat
n
(abbr 缩写 ct)
1 unit of weight (200 milligrams) for precious stones 克拉(宝石重量单位, 等於200毫克).
2 (US karat) unit of measurement of the purity of gold (pure gold being 24 carats) 开(黄金纯度单位, 纯金为24开)
a 20-carat gold ring20开的金戒指
a ring of 20 carats 20开的戒指.