Perhaps the most impactful of the 4 Cs, diamond cut describes the proportions and facets of a diamond. Proportions include the diamond’s height (also called ‘depth’), width, and table size (the table is the large, flat face on top of the diamond). Facets are the tiny planes cut symmetrically into the diamond. A well cut diamond will absorb plenty of light. The light will then bounce around the facets before being reflected back out into the world.
Diamond cutters must be extremely skilled and meticulous to create well cut diamonds. Even the smallest deviations from ideal faceting and proportions can have a major effect on the final product. Diamonds that are too deep or too shallow, too narrow or too wide, will not absorb light properly. They'll lose light either from the sides or the bottom–a process referred to as light leakage. The less light a diamond absorbs, the less light gets reflected off the facets and back into the world, resulting in a duller diamond.
Diamonds are judged based on their lack of color. Fully transparent, colorless diamonds are considered the most valuable. It’s exceedingly rare to find a diamond with no hint of color. However, most diamonds sold in jewelry stores are so faintly colored that you can’t even tell they have any tint at all. Still, it’s a good idea to familiarize yourself with diamond color grading, which is judged on an alphabetical scale.
D-F: Completely colorless. The rarest possible grades.
G-J: Nearly colorless. Diamonds with these grades are commonly used in jewelry, since the tint is essentially invisible to the naked eye.
K-M: Very faintly colored. Some light yellowish or brownish tint may be visible if the diamond is large, or if you look very closely.
N-R: Faintly colored. Some light yellowish or brownish tint is visible, especially if the diamond is large, or if you are looking closely.
S-Z: Lightly colored. A yellowish or brownish tint is obvious. Diamonds tinted beyond a grade of Z are called "fancy colored diamonds" and are no longer considered white diamonds at all.
Jewelers judge a diamond's clarity based on the presence of any flaws. Diamonds are created through natural processes. Even lab grown diamonds are created in chambers that mimic the conditions by which diamonds form within the earth. Mother Nature is not perfect, and neither are the diamonds she creates. Diamond flaws can be divided into two categories: inclusions and blemishes.
Inclusions are flaws within the structure of the diamond, such as trapped gas bubbles or small pieces of other minerals. Blemishes are flaws on the surface of the diamond, such as tiny pits or shallow scratches. Most flaws in jewelry-quality diamonds are too small to be seen with the naked eye, but jewelers still have a grading system that takes these into account.
FL: Flawless. This is an incredibly rare occurrence.
IF: Internally flawless. A diamond with no internal flaws, but some very minor blemishes (invisible to the naked eye).
VVS: A diamond with inclusions or blemishes that can barely be seen by a skilled jeweler under 10x magnification. Broken down into VVS1-VVS2, with VVS1 being less included.
VS: A diamond with inclusions or blemishes that can be seen by a skilled jeweler under 10x magnification. Broken down into VS1-VS2, with VS1 being less included.
SI: A diamond with inclusions or blemishes obvious to a skilled jeweler under 10x magnification, and possibly visible to the naked eye. Broken down into S1-S2, with S1 being less included.
I: A diamond with inclusions or blemishes visible to the naked eye. Broken down into I1-I3, with I1 being the least included.
Carat is the measurement of a diamond’s weight. One carat is equal to 0.2 grams. It takes 5 carats to add up to 1 gram, which is about the weight of a standard paperclip. When you think about it that way, you come to understand just how light diamonds really are–and be impressed by all the beauty they can fit into such a small package!
