THE 4 C’S
When you browse diamonds, you’ll want to pick the diamond shape that’s important to you, but on a physical level, not all diamonds are made equal. Diamantaires divide diamonds based on the 4 C’s, which are the elements that make a diamond the incomparable treasure that it is. Color, carat weight, cut, and clarity are graded by reputable organizations like GIA and AGS, giving a shopper the ability to understand what they’re paying for when they select a given diamond.
Diamonds are also known for their scintillation (white flash) and fire (rainbow flash). But without faceting, diamonds would be no more vivid than a piece of glass. Diamantaires do extraordinary feats of geometry and physics to determine how to perfectly cut a given shape to maximize its sparkle, but not every diamond is ideally cut. Diamonds that have been poorly cut will allow light to seep out the sides rather than refracting and reflecting light. GIA grades diamonds from ideal to poor, grading a stone on how well it conforms to mathematical standards.
One of the most iconic features of a diamond is its icy white clearness. However, very few diamonds fall into the category of completely colorless. While a pure diamond is made exclusively of carbon, most diamonds will have some nitrogen impurities that turn the stone shades of yellow or brown. GIA grades diamond color from D to Z, with D – F being considered grades of colorless, and Z being extremely yellow. Because of their rarity, D – F diamonds will cost more than comparable stones.
We mentioned that diamonds are clear, but that’s not always the case. Gas isn’t the only impurity that can get trapped in a growing diamond. Iron, sand, black carbon, smaller stones, and more can be found inside diamonds, as well as natural defects in the crystal structure of the diamond. These inclusions can affect the way light travels through the stone, break a ray of light, or simply be unwanted “dirt” inside the diamond. GIA makes sure to point out the location and type of inclusions or defects in diamonds, using 10x magnification to grade a diamond from FL (flawless) to I3 (extremely visibly included), with 9 gradations between those two.
Carat is best thought of “how much” diamond is in a given stone. A measurement of weight, 1 carat is equivalent to 0.2 grams. Colloquially, carats are thought of as “volume” rather than “weight,” but when shopping for a diamond, it’s important to remember that a compact shape like the round cut will appear significantly smaller than a long shape like the emerald cut, even if the two diamonds have the same carat weight. Because diamantaires prefer selling stones by 1- and 0.5-carat increments, it can be more affordable to pick an off-size diamond of comparable size (such as a 0.9 carat rather than a 1 carat diamond).