Know the Grading Standards

Diamond quality is based on the four Cs of quality; Carat, Color, Clarity, and Cut. Understanding the key to each of these grading standards in the same way that a diamond reseller does, you will gain the ability to confidently buy your diamonds online and know you are getting a great deal.

Carat

Sometimes referred to as 'carat weight', this is the most simple measurements of a diamond's quality that can be made. Carat was the first measure, used in ancient times, to determine the value of a diamond. The unit of weight for a carat comes from the carob seed. These plant seeds are incredibly consistent in weight and even modern measuring instruments can find only an extremely slight variation in the differences in weight among them. Carat was used to determine a diamond's weight until the turn of the nineteenth century when it was replaced by the metric system.

Color

Next to cut, color is the most important part of a diamond's quality that can be distinguished by the human eye. The vast majority of diamonds have slight tens of yellow or brown in them. The color of a diamond is determined by comparing it to a set of master stones in a lab. Some diamonds can be colorless, while others will grade as a light yellow. The scale for grading the color of a diamond ranges from D to Z alphabetically with D being absolutely colorless and Z having the most yellowing of the stone. An average stone in the marketplace will have a rating between I-K and most people cannot see a difference in coloring until a diamond reaches the L-M-N range. Diamond colors are rated as follows:

D-F is absolutely colorless, G-J is near colorless, K-M is a faint yellow, N-R is a very light yellow and S-Z is a light yellow. The most valuable diamonds are in the colorless range. Nature only very rarely produces a diamond with the more fancy colors like blue or champagne.

Clarity

The clarity of a diamond speaks to the internal birthmarks of a diamond. Usually these birthmarks (or flaws) are only visible under intense scrutiny or magnification. When a diamond is subjected to magnification of 10 powers, it can be rated based on whether it is flawless, vvs1, vvs2, vs1, vs2, si1, si2, I1, I2, or I3. One of the most common benchmarks for determining the clarity of a diamond is whether or not you can see it with your own eyes. The most valuable diamonds have no flaws that can be seen with the naked eye. Flawless diamonds are extremely rare while I3 diamonds are only rarely for sale in the serious jeweler's market.

Cut

Cut is the most important and complex part of the five Cs. This is the part that is not handled by nature, but by the expert hands of a master craftsman. How precisely a diamond is cut determines it's fire, brilliance, and ultimately, just how beautiful the diamond will be. A poorly cut diamond does not reflect light well and will diminish the stone's overall attractiveness. Diamonds that are cut too deeply spill their light out of the bottom of the stone, leaving the rest of it appearing dull.

The cut of a diamond is graded from excellent through fine, good, fair, below average and the "R" or recut ratting for a very poorly cut stone. Cut also affects the carat of a diamond, and there is enormous pressure put on diamond cutters to maximize a diamond's carat when making their cuts, so that the stone will retain most of its value.