Other shapes besides round can be faceted as brilliant cuts, including oval, radiant, pear or heart. Carat is the unit of weight, equal to 200 milligrams. In ancient times one carat was equal to one carob bean or four grains of rice. Carbon Spots are the name often used for black spots in diamonds. This is misleading since these spots are certainly not coal, but usually transparent diamond crystals within the main diamond.
Clouds are hazy or milky areas in a diamond.
Most clouds are made up of crystals too tiny to see individually even under a 10X magnification. Crown is the upper part of the diamond above the girdle. Culet is the tiny facet on the pointed bottom of the pavilion, parallel to the table. Cut refers to the geometric proportions of a gemstone. The cut of a gemstone is one of the most important factors in determining how much sparkle a gemstone produces.