"Hi, I'm Lumi! If you only remember one thing about buying a diamond, make it this: Cut is King."
What is Diamond Cut?
When people hear "cut," they often think of the shape (like Round or Oval). But in diamond grading, Cut actually refers to how well the diamond interacts with light.
It's the geometric proportions, the symmetry, and the polish of the stone. A well-cut diamond reflects light back out the top, creating that breathtaking sparkle. A poorly cut diamond leaks light out the bottom, making it look dull and lifeless.
The Anatomy of Sparkle
There are three ways a diamond interacts with light:
- Brilliance: The white light reflecting from the surface and inside the diamond.
- Fire: The flashes of rainbow colors.
- Scintillation: The pattern of light and dark areas (contrast) you see as the diamond moves.
Why You Should Never Compromise on Cut
You can hide color in a gold setting. You can hide clarity under a prong. But you cannot hide a bad cut.
A poorly cut diamond will always look dull, no matter how flawless its clarity or how perfectly colorless it is. In fact, an Excellent cut diamond with a lower color grade will almost always look more beautiful than a Fair cut diamond with a perfect D color.
The Lumi Verdict
Always, always, always prioritize cut. For round diamonds, only accept Excellent or Ideal cut grades from GIA or AGS. For fancy shapes (like Ovals and Emeralds), look for Excellent polish and symmetry, and rely on videos to verify the light performance.