There are four Cs that are used to describe a diamond: cut, color, clarity, and of course, carat. The carat is the standard unit of measurement used to indicate the weight of diamonds and precious gemstones. Since 1913, carat weight has been gauged against the metric system, with one carat equaling 0.2 grams or 0.007 ounces. Carat weight is measured to three decimal points and rounded to the nearest hundredth.
1 carat single diamond is far expensive in comparison to 1 carat total weight of smaller diamonds in group