Diamond Cut

Diamond Cut

General Facts

  • Today we are going to be talking about another one of the 4 C’s: diamond cut.
  • The cut is extremely important because it has the largest influence on a diamond’s sparkle.
  • When we talk about the cut, we are referring to the actual proportions of the diamond, not just the shape.
  • In the jewelry industry, each cut in a diamond is known as a facet. These facets will interact with light differently depending on the proportions of the stone.
  • The cut grading helps determine how well light is able to travel through the diamond and return to your eyes.
  • A diamond at the highest color and clarity can still appear dull due to a poor cut.

How is Cut Graded?

  • GIA grades cut on a five-point scale ranging from Excellent, Very Good, Good, Fair, and Poor.
  • When a diamond is cut to ideal proportions, the light will travel through and exit from the table on top.
  • If a diamond is cut too shallow, it may look larger than others at the same weight, but it will not be as bright because the light is leaking out from underneath.
  • If a diamond is cut too deep, it may look smaller than others at the same weight, but the brightness is still compromised because the light will leak to the sides.
  • When shopping for diamonds, you will hear these 3 words used often to describe cut:
    • Brilliance is the play of brightness and contrast within a diamond.
    • Fire refers to the light that is refracting out of the diamond as flashes of rainbow color.
    • Scintillation is the intense glittering sparkle created by the dark and light contrast within a diamond.
  • It is important to look for an even distribution of brightness and contrast within the stone.

Why Don’t All Shapes Get A Cut Grade?

  • Although cut is important to all diamond shapes, round diamonds are the only shape that will receive an official cut grade by GIA. AGS, one of GIA’s many competitors, assigns a cut grade to round and princess cut diamonds.
  • There are virtually endless patterns of cutting styles for a diamond. The traditional round brilliant cut is the shape with the most brilliant type of facets that are known for returning the maximum amount of light back to your eyes.
  • Due to the variation among fancy shape cuts, such as the marquise, pear, oval, etc.,  there is no agreed upon standard for grading cut.
  • Aside from the cut grade, all diamond shapes will receive a polish and symmetry grade which we can use as a tool to infer how well it is cut.
  • Polish and Symmetry are graded on the same 5 point scale as cut
  • Polish refers to the smoothness of each facet after being cut.
  • Having great symmetry ensures that the facets are perfectly aligned and spaced correctly for maximum light scintillation.

Our Recommendations

  • To maximize the brilliance of your diamond, we recommend shopping for a cut great of Very Good or better.
  • This added brilliance can actually do more than just look pretty.
    • By prioritizing on a higher cut grade, chances are that the play of light will distract your eyes, which can make other aspects of the diamond look better.
    • A well-cut diamond may look better in color than a poorly cut diamond, although they are graded the same.
    • An excellent cut can also help camouflage inclusions by distracting your eyes with sparkle and making it more difficult to see them.  
  • There are many tools available to help you determine how well a diamond is cut, but remember to always let your eyes be the final judge. We recommend viewing your diamond in multiple lighting settings to help you make the best decision.


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