The 4 C’s of Diamonds

Part IV - The Carat Weight

The word Carat comes from the ancient Greek Name for the Carob Seed (Keration) which, due to its consistent size and weight, was once widely used as a counterweight for weighing Diamonds and Gemstones.

The CARAT (metric carat) is the Standard International unit of weight for Diamonds, Coloured Gemstones and Pearls.

1 CARAT = 1/5 (0.2) gram

The carat is further divided into POINTS, a unit of weight used only for Diamonds.

1 POINT = 1/100 (0.01) carat


Size & Carat Weight

A Diamond’s Size-to-Weight relationship varies according to its proportions. On average, a well made 1 Carat, Round Brilliant Cut Diamond has a diameter of around 6.5mm.

Carat Value

In determining the carat value of a finished Diamond, each of the 4 C’s is considered. For each step of improvement in Clarity or Colour the value is increased. As the Carat weight increases the premium factors for both Colour and Clarity are also increased.

Cut Quality & Carat Value

The quality of the Cut can have the greatest influence on value. Superior Cuts take more time, require greater skill and yield lower finished weights, adding significantly to the overall cost and ultimate per Carat Value.