The 4Cs are the key characteristics of diamonds:
carat, cut, color and clarity.

Carat

A diamonds size is measured in Carat Weight. Each diamond carat is also equal to 100 points. For example, a diamond that is a ½ carat can also be referred to as a 50 point diamond.

Cut

The cut of the diamond is also referred to as the shape. Shapes include Round Brilliant, Princess Cut, Emerald Cut, Marquise Cut, Oval Cut, Radiant Cut, Pear Shape, Hear shaped and Assher Cut. When a diamond is cut to good proportions, light is refracted from one facet to another, then dispersed through the top of the diamond. A well cut diamond – regardless of its shape, sparkles, has more fire and offers the greatest brilliance.

Color

Color is the natural body color visible in a diamond and is the one C determined completely by nature, not man. As a rule, the closer a diamond is to colorless, the more valuable and beautiful it is. Diamond colors appear in a range from D to Z. Color grades D, E and F are considered colorless, making them rare. G, H and I are near colorless and J down are going to have a considerable amount of color.

Clarity

Clarity is an indication of a diamond's purity. When a rough stone is extracted from carbon, deep beneath the earth, tiny traces of natural elements are almost always trapped inside. These elements are called inclusions, though sometimes referred to as birthmarks, because they are formed naturally and are unique to each stone. Clarity ranges from internally flawless (IF), very very slightly included (VVS1-VVS2), very slightly included (VS1-VS2), slightly included (SI1-SI3) and Included (I1-I3)