0.5 Carat Diamonds are said to be 100 milligrams or 1/10 grams. Carat is the unit used for the weight of a diamond. The dimensions of a 0.5-carat diamond depend on its size, cut and clarity. Usually the diameter of 0.5 Carat Diamonds is 5.1mm. Higher quality diamonds tend to be more expensive than lower quality diamonds (eg diamonds with higher colour, size and clarity are more valuable). Visit our online store for more information and to purchase 0.5-carat diamonds.