It’s important to remember that a diamond’s value is determined using all of the 4Cs, not just carat weight. One carat is subdivided into 100 points. This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its points alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer’. Diamond weights greater than one carat are expressed in carats and decimals, for example, a 2.08 carat stone. Two diamonds of equal carat weight can have very different values and prices depending on the remaining three grading factors.

The color evaluation of diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water. It consequently has a higher value. The Gemological Institute of America’s (GIA) uses a D-to-Z color grading system to measure the degree of colorlessness. By comparing a stone under controlled lighting and with precise viewing conditions, it is the easiest way to establish color value.

This is the industry’s universally accepted grading system. Beginning with the letter D, representing colorless, and continuing with an increase presence of color, all the way to the letter Z. Many of these color distinctions are so subtle that they maybe invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.