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Grading Diamonds

Grading Standards evaluate three of the four value factors--cut, color and clarity. The three factors are expressed separately along with the fourth factor, the carat weight of the stone, for the final Grade.


One of the most important factors in determining quality in diamonds is the cut. Cut is the only value factor that is a result of human skill. A diamond's beauty must be balanced against the inevitable loss of weight necessitated by the very process of cutting. Along with the diamond's size and shape, the minute details of workmanship play an important role in the overall beauty and sparkle of the diamond.


It is important to remember that cut is the most critical of all the variables effecting the value of a diamond, more critical even than the carat weight. It is thus essential that you be well advised of the quality of the cut when purchasing a diamond.


A truly colorless diamond is extremely rare; most diamonds possess various degrees of yellow or brown. Small, subtle differences in color can make a substantial difference in value. Although increasing shades of yellow reduce the value of a diamond, they do not necessarily reduce its beauty. If a diamond is well cut, refraction and dispersion will often disguise certain degrees of coloration.

Unless a diamond is a fancy color, the Color Grading System places it on an alphabetical scale from D to Z. D being colorless.


To accurately and consistently color grade, a trained gemologist must utilize special lighting to compare the diamond being graded to a set of Master Diamonds, which have met exacting standards of cut, color and carat weight. The diamond is viewed face-down and reassessed face-up for the most accurate, consistent grade.


Clarity is the evaluation of a diamond's internal and external characteristics. Inclusions are internal, that is, inside the diamond. Blemishes are usually very small and are only on the surface of the diamond.


Two of the most common inclusions are crystals and feathers. Crystals are merely minerals trapped inside the diamond. Feathers are breaks in the diamond.


One must use a binocular microscope that magnifies the diamond ten times to locate these tiny characteristics. Then, evaluating the size, location, number and color of all inclusions and blemishes, a clarity grade from IF to I is assigned. IF represents a diamond that is Flawless. Every diamond is plotted for clarity from the top (crown) and bottom (pavillion) views, with the table size (large top facet) printed on each grading document in its actual percentage dimension.

Carat Weight

The fourth and final C is carat weight, the standard usually used to measure diamonds. A carat equals 1/5 of a gram (or 1/142 of an ounce), each carat is further divided into points, each point representing 1/100th of a carat. In the final analysis, weight may be the least important of the four C's in determining value. Indeed, comparing the value of stones by weight is not unlike comparing the value of paintings by size. After all, a "sofa-size" painting by an unskilled artist may weigh more than a miniature by Rembrandt but we assure you that it will not be worth more.


Weight may be the easiest of the four C's to gauge accurately. All that is required is a delicately balanced scale capable of weighting extremely small weights. Yet despite the ease of measurement and the relative unimportance of diamond weight, there are some facts you should understand about weight and price.


For one, as diamonds increase in size, their cost tends to increase geometrically rather than arithmetically. Thus, a one carat diamond can cost four or five times as much as a one-half carat stone of equal quality. For another, as implied previously, weight does not always enhance the value of a diamond. In fact, when a stone is improperly cut, added weight may serve only to reduce its brilliance. For these reasons you should consult with a skilled gemologist regarding the question of carat weight, especially as it relates to the quality of the diamond's cut.