When shopping for a diamond many consumers are introduced to the 4 "C's" of diamonds to determine what sort of diamond they will ultimately purchase. These of course are Color, Clarity, Carat Weight, and Cut. The first three C's are fairly straightforward. Color is the whiteness of diamond, Clarity is how free of inclusions and imperfections a diamond is, and carat weight is how much a diamond weighs on a diamond scale. The fourth C however, is a little more complicated. What exactly makes certain diamonds better cut than others? A lot of it has to do with the what shape the diamond is, but other than that, many customers are unsure how to compare a diamonds based on cut.
Diamonds with laboratory reports will usually have some information pertaining to how diamond is cut. The two characteristics most easily recognized are a diamonds depth percentage and table percentage. Depth percentage refers to the "height" of a diamond top to bottom, and table percentage refers to the size of the topmost and largest facet on a diamond. Both of these percentages are relative to the millimeter diameter of a diamond. The ideal proportions of these characteristics vary depending on the shape the diamond, however, for round diamonds 60% is generally accepted as a benchmark for both of these variables. The GIA and AGS are currently the only laboratories that give cut "grades", and these are only given to round diamonds.
How these proportions determine how a diamond actually LOOKS is what is most important when shopping for a diamond. Generally, diamonds with higher depth percentages look smaller than their carat weight suggests, and often have a darker appearance. Diamonds with lower depth percentages look large, but sparkle less and appear glassy. Smaller table percentages are associated with a greater degree of sparkle, whereas larger tables have a tendency to make the diamond appear too transparent.
Although these rules still apply to determining the brilliance of a fancy shape diamond, they are most consistent when comparing the classic round diamond. Other shapes have a tendency to be cut deeper (mainly to save weight) than rounds so they often look smaller.
When shopping, be sure to understand how the cut of a diamond affects its apparent size and brilliance. And how the various shapes of diamonds are typically cut. You can click on the link below to learn some more about the various characteristics examined when describing cut.
What Determines a Diamonds Cut?