June 4, 2011. Bill Szydlowski
credit: Per Ola Wiberg ~ PowiWhen it comes to grading diamonds, there are many factors that are taken into account. Generally, the most important factors are the cut of the diamond, its carat weight, the color of the diamond, and its clarity. A gemologist must use some universal tools in order to determine the color and clarity of a diamond.
The most valuable diamonds are those that have absolutely no color. A gemologist can determine the amount of color in a diamond by viewing it in a specific type of light and comparing it to a diamond color chart. There is a scale that goes from D to Z, with D being considered a completely colorless diamond. A rating of Z means that the diamond is the darkest shade of what is considered “light yellow”. Darker yellow diamonds are considered “fancy light“, “fancy” and “fancy intense”.
It is also very important when buying a diamond to know how clear the diamond is. A stone that has many inclusions in it can appear milky or cloudy, and the inclusions can actually weaken the structure of it. One way to tell how a diamond rates when it comes to clarity is to compare it to diamond clarity charts. The chart is compared to the diamond being graded, and a gemologist can then tell what grade to give the diamond. Grades range from VVS, meaning very, very slight inclusions to VS meaning very slight inclusions, and on to SI, meaning slight inclusions. The final grade given is I, or included. Diamonds in this category have flaws that are able to be seen without using any magnification, and should be avoided except when they are used in inexpensive fashion jewelry.
Buying diamond jewelry can be a scary prospect, especially when paying quite a bit of money for the diamond. It is always important to select diamonds that have certificates accompanying them, so you know exactly what you are paying for. The diamond color chart and the diamond clarity chart are certainly two of the most important tools used by jewelers to grade and value diamonds for consumers.
Updated June 4, 2011. Published May 28, 2011. Bill Szydlowski
