There are four universally accepted characteristics that grade diamonds. They are recognized as the 4 C´s: Carat, Cut, Clarity, and Color. A diamond´s value is based on a combination of these four categories. By modifying these characteristics, you can find the best diamond for your desired price.
A carat is a measure of weight, which also indicates size. Diamond carat weight is the measurement of how much a diamond weighs. A metric "carat" is defined as 200 milligrams. A diamond’s total carat weight is determined by the minimum weight of all the diamonds in a single piece of jewelry. For instance, if a pair of diamond studded earrings has a total carat weight of 1/2 (.50) carat, then each earring in this pair would have an individual carat weight of 1/4 (.25) carat.
The carat weight of a diamond is one of the major factors affecting its price (along with cut, clarity and color). Larger diamonds are rarer than smaller ones, so the value will also increase exponentially for higher carat weights.
As diamond’s carat size increases, both the diameter and the depth of the diamond also increase. A 1/2 carat diamond is approximately 5mm in diameter while a 1 carat diamond is approximately 6.5mm in diameter.
A diamond cut to proper proportions allows the greatest amount of light to be reflected for maximum brilliance. A well-cut diamond will give the best return of light, appearing fiery and radiant. If a diamond is poorly cut, it may appear dull and lifeless (even if it has good clarity and colour grades). Out of the 4Cs, cut is the most important factor to consider as it is this that has the biggest impact on the stone’s sparkle.
The fewer imperfections in a diamond, the better. A flawless diamond is EXTREMELY rare and valuable. Diamond clarity refers to the absence of inclusions and blemishes. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called 'inclusions' and external characteristics called 'blemishes.'
Diamonds are found with a range of colors, from light yellow or brown through no color at all, the rarest. GIA's diamond D-to-Z color-grading scale is the industry's most widely accepted grading system. The scale begins with the letter D, representing colorless, and continues, with increasing presence of color, to the letter Z. Many of these color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.