At the simplest level, cut is the way the diamond has be cut into a shape, for example, round brilliant cut, marquise cut, princess cut, etc… the shape the rough diamond has been fashioned by cutting. However, the deeper meaning of cut has to do with the proportioning of the diamond when it is being cut. There is a standard for cutting round diamonds, and it is judged against a mathematical ideal. There are few diamonds that are absolutely perfectly ideal proportions, but most are cut within an acceptable range of “ideal”. Diamonds that are cut outside too far out of the ideal range have diminished brilliance, fire, and scintillation.

If two diamonds are the exact same carat weight, clarity, and color, but look very different; one having less brilliance, fire, and scintillation, the fault lies in the cutting. A careful examination will show the diamond’s facet angles and proportions do not come up to the standards of a perfectly “ideal” cut diamond. The cutter may have chosen to sacrifice some brilliance to gain a greater carat weight.

Since fancy cut diamonds (marquise, pear, princess, oval, emerald cuts, etc…) are invariably designed to take advantage of odd shaped diamond rough, they usually yield about the same finished weight to rough as a round brilliant cut diamond, and hence are priced comparably. However, pricing of fancies does depend on quality of the diamond. It’s not possible to set precise pricing guidelines because each diamond has to be judged individually. Like people, no two diamonds are exactly alike!

Most diamonds that are used in jewelry appear colorless or clear to the eye, yet with few exceptions, all diamonds have a hint of body color. Completely colorless diamonds are extremely rare; only a very small percentage of gem quality diamonds fall into this category. Top graded colorless diamonds command prices well above the next best colors. In the accepted grading scale used by the Gemological Institute of America (GIA), a colorless diamond is given the grading of “D”. Before a universal color grading scale was determined, many jewelry stores had used the letters, A, B, and C, to grade the diamonds in their inventory. GIA started the color grading scale with the letter D in the alphabet so as not to confuse with the color grading scale of A, B and C that was already being used. While the top color grade is D, all other diamonds are graded below this in the alphabet; E, F, G… and so on. While the relative difference between a “D” and an “E” diamond may be discernible only to the most expert eye, that slight grading difference can translate into a much higher price for the “D” graded diamond.

Diamonds with a tinge of body color are considered less desirable, however, a diamond with intense color, such as a pink, blue, or canary colored diamond are considered to be very valuable. Such diamonds are rare, particularly the blues and pinks, and even rarer, green colored diamonds. Diamonds do occur in virtually all colors of the spectrum and these colored diamonds are called “fancies”. The deeper colors have great beauty, however they usually do not have the brilliance of the lighter colors.