We talked last week about how each of the 4 C’s: Cut, Color, Clarity and Carat Weight affect the price of a diamond. All of the characteristics of a diamond also work together towards creating a beautiful diamond. There’s no point to a huge diamond that weighs 10 carats but has a poor cut, ridiculously included clarity grade, and a subpar color grade. Those are what we call industrial diamonds, and they get ground up and used for tools (and occasionally nail polish.) Likewise, a diamond with 2-3 good grades will have its entire diamond GPA lowered by one bad grade. No one wants a decent sized, well cut, nicely colored diamond that looks like “frozen spit” clarity-wise, to borrow a term from one of our eloquent Facebook commenters.
So yes, all four C’s are important, and they all combine to make a diamond great. However, there’s one C that’s more heavily weighted, and that determines a diamond’s beauty more than any of the other factors. If you’re a regular reader, you already know what we’re about to say. Cut is the most important of the 4 C’s.
Cut, the most complicated of the diamond characteristics, is understandably the most vital. Cut essentially refers to how well a diamond’s facets interact with light. Cut is determined by three factors:
- Brightness, the internal and external reflection of white light from the diamond.
- Fire: The scattering of white light into all the colors of the rainbow.
- And Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond. The “cut” grade refers to the diamond’s ability to produce all three with maximum results based on its proportions.
On the left we have a 3.01 carat, J color, VS2 clarity grade. The diamond on the right is a 3.06 K color, SI1 clarity grade. However, the diamond on the right has an excellent cut grade, while the one on the left is only fair. The one on the left, for its better color and clarity, looks dull, lifeless and dirty next to the stone with the better cut.
So what’s the magical proportion? There isn’t one! According to GIA Senior VP Thomas M. Moses:
“The most exciting and reassuring conclusion of our research is that there is no single set of proportions that define a well-cut round brilliant diamond. Our research has shown that many different proportions can produce attractive diamonds.”
So whether a diamond has 57, 58 or less facets, it’s all about how precisely they’re cut to maximize a diamond’s beauty. A diamond cut too shallow or too deep won’t sparkle, shine and wow like it could with an excellent cut.
You want to be in the sweet spot – somewhere between shallow and perfection – to maximize your budget. A diamond that looks large (so it may have a slightly shallow cut) but isn’t affected by the slightly stretched portions will cost less per-carat because of its cut (and its lighter carat weight) but you won’t sacrifice the beauty of the stone.