THE FOUR C'S

COLOR
Diamonds range from colorless (or rare white) to varying shades of yellow, brown or gray. There are other colors which occur, but these are the most common.

CLARITY
Diamonds range from being flawless (without internal imperfections or blemishes on the surface), to having degrees of imperfections. A diamond with obvious imperfections will be less expensive for two reasons: (1) It is less rare, mineralogically (more diamond crystals have imperfections than not), and (2) More people prefer the look of a diamond that does not have obvious imperfections, especially to the naked eye.

CUT
Diamonds range from having proportions which create the maximum amount of brilliancy, symmetry and durability, to cuts which sacrifice one or the other, usually in an effort to retain as much weight as possible from the original diamond crystal.

As a guideline, I rank cut using the AGA Cut Class Scale: 1A-1B, 2A-2B, 3A-3B, 4A-4B, which basically is a more detailed extrapolation of the GIA Cut Class Scale 1 to 4. In laymen’s terms, a description of these cut classes would run along the lines of 1A- Ideal Make, 1B- Premium Make, 2A- Very Good Make, 2B- Good to Very Good Make, 3A- Good Make, 3B- Fair to Good Make, 4A- Fair Make & 4B Poor Make (this appraiser’s synopsis of the AGA Cut Grading Scale).

A diamond with a “good” cut (3A-3B) is an average, reasonably well made jewelry diamond that is brilliant and pleasing to the eye. Anything less than that is below the average (fair- 4A, poor- 4B), and anything more than that is above the average (very good 2A-2B, exceptional 1A-1B).

Millimeter Dimensions, Total Depth, Table Size, Crown Height, Pavilion Depth, Girdle Thickness, Culet Size, Symmetry and Polish are listed on diamonds 0.70 ct. and larger to give the client a complete picture of the diamond’s cut. When appropriate, a Light Return Analysis generated by the state-of-the-art Moscow Universtiy DiamondCalc software is created using a computer simulated IdealScope image. Examples are pictured below. The red areas in the images indicate high light return, with pink areas indicating lesser light return, black areas indicating high contrast, gray areas indicating lesser contrast & white areas indicating light leakage. The majority of diamonds will have some light leakage, the less the better. A balance of red and black is good for contrasting scintillation. *Note- the program is only capable of generating “excellent” symmetry.

CARAT WEIGHT

Diamonds are weighed on the basis of “carats”. Five carats equals one gram in weight. A carat is then subdivided into 100 “points”, with a full carat weighing 100 points or more, a three quarter carat weighing approximately 75 points, a half carat weighing 50 points or more, etc.

Most rough diamond crystals mined yield an average of one third of a carat. To find a crystal which yields a half carat is more mineralogically rare, and a crystal which yields a three quarter carat, one carat, etc. Consequently, the larger the weight, the more dramatically the price jumps. A one carat may cost four or five times as much as an equivalent half carat.

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