Diamonds: How are They Valued?

Diamonds, Ice, Sparklies, A Girl’s Best Friend: Whatever you call them how are they valued? The four C’s -- Cut, Clarity, Color and Carats. We'll talk about the first three C's here.

Cut: A diamonds’ cut influences the brilliance, or light reflecting qualities of the gem, at the same time it enhances the fire of the diamond, or that rainbow quality. A good cut enhances both qualities, fire and brilliance, without sacrificing one for the other. A well cut diamond balances the depth of the diamond to the breadth of the diamond. A poorly cut diamond of the same size can look flat and be more vulnerable to cleavage and breakage.

Clarity: Diamonds are crystalline carbon. The clarity of the diamond refers to the purity of the stone and imperfections within the crystalline structure and on its surface. There is no such thing as a flawless diamond in nature. Sometimes this clarity factor is referred to as the cleanliness of the stone. If a stone is viewed under 10x magnification and no imperfections can be seen, either internally (inclusions) or externally (blemishes), the stone is referred to in the trade as flawless. A microscopic speck of carbon, undetectable by the human eye, but visible under 10Xmagnification,can bring down the value of the diamond substantially. There are five commonly used methods for grading clarity. Just keep in mind the cleaner the stone, the more valuable it is, the more it costs.

Color: Diamonds come in colors including black. Most of the darker colors are used for industrial purposes and not for gems. The white-blue color of pure water is the most valued color for white diamonds and these are rated D-F. (There is no A-C on the scale.) As the diamond color progresses toward yellow (K-M) it becomes less valuable. Diamonds that have a noticeable yellow (N-R) to champagne color (S-Z), are the least valuable. Because the color can be influenced by the color of the gem’s setting, the color is judged when the stone is unset.

To complicate matters and value, diamonds that come in colors, called fancies, are very rare and very valuable. Deep blue, red, and green diamonds are among the rarest and most valuable gems on earth.

When purchasing your diamond for your engagement and wedding rings, consider what factors are more important to you. Size might be more important than color so a larger diamond with a barely noticeable yellow tinge might make you happier than a blue white smaller diamond.