The 5 Cs of Diamonds
Diamonds are always measured in carat weight. One carat is the equivalent of 1/5 of a gram. Additionally, there are "100" points in a carat, so that a .50 "point" diamond would be described as a half-carat.
Almost every diamond will contain some blemishes, and inclusions formed during the course of its crystallization. The diamonds clarity grade refers to the visual impact of these characteristics or lack thereof, as viewed under 10X loupe magnification. There is a grading structure (GIA clarity grading scale) used to describe inclusions found within the diamond.
The "color" of a diamond refers to the presence or absence of inherent coloration in a white diamond. The whiter the diamond is the greater its value since a colorless diamond will allow increased light to pass through it and will consequently emit a greater amount of fire and brilliance.
Cut is the most misunderstood and underestimated "C" of the five "C's". Cut is properly referred to as the "make" or quality of the way the diamond has been crafted. "Cut", should never be confused with the "shape" of the diamond. The cut of the diamond is the only "C" that is entirely manipulated by the diamond cutter, and will determine the beauty and value of the diamond.