Diamond - 0.41 ct - Briliant - Fancy Grey Brown

Diamond : In mineralogy, diamond is an extremely rare, precious and hard (named after the ancient Greek "unbreakable") metastable allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice.
Carat : The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.