Education - Cut


  • Cut can be considered a diamond’s most important characteristic as it has the greatest overall influence on a diamond’s beauty, and therefore value.
  • It determines a diamonds brilliance which we generally think of as its overall sparkle.
  • We at Lover’s Rock recommend selecting the highest cut grade within your budget, as no other of the Four Cs characteristics has a greater influence on a diamond’s appearance.

    A diamond’s cut grade is an objective measure of how well a diamond handles light, which determines the overall brilliance or sparkle of the diamond. When a diamond is cut with the proper proportions, the maximum amount of light reflects back out of the top of the diamond. If it is cut too shallow, light leaks out of the bottom; too deep and it escapes out of the side. The less light reflected back out the top of the diamond, the less brilliance or sparkle a diamond emits.


    • Excellent or Ideal cut: Reflects nearly all light that enters the diamond offering the most Brilliance and sparkle, making it one of the most valued and cherished cut grades. In some cases, when an excellent cut diamond reflects a vast amount of light, it can be upgraded to the exceptional and rarer ‘Ideal Cut’.
    • Very good cut: Reflects nearly as much light as the excellent cut. However, as the difference between the two is almost unrecognisable to the unaided eye, very good cuts offer better value for money.
      Good cut: Reflects most light that enters, allowing only a small amount to escape. The difference between this cut and the very good cut is minimal. However the cost is substantially cheaper, making good cuts a much more affordable option.
    • Fair cut: Still a quality diamond that sparkles, but when compared to higher cut grades, fair cut will not emit as much brilliance.
    • Poor cut: Diamonds that are generally so deep or shallow that they lose most of the light out the sides and bottom, therefore reflecting hardly any light back through the Diamond. Lovers Rock does not carry diamonds with cut grades of poor.


    • Finest quality: Ideal and Excellent
    • Best balance between quality and cost: Very good
    • Biggest size at an affordable price: Good
    • Here's some more technical information on diamond cut:
  •  Here's some more technical information on diamond cut:
      • Symmetry: Symmetry is when the facets of a diamond are well balanced and aligned with each other, which is critical in creating optimum brilliance and sparkle. Factors which can affect symmetry include off-centre tables, unequal facets, and also the thickness and consistency of the girdle.
      • Fire: The flashes of coloured light which reflect back from within a diamond, similar to a prism. Higher grade diamond cuts will in general refract more colours when turned in the light.
      • Polish: Polish describes how smoothly the facets of a diamond have been polished after a diamond has been cut. A polish of a high degree is where a diamond has no scratches or very minor ones. Where scratches, lines, burn marks etc. are visible the polish rating of a diamond can be downgraded and if significant, could affect the overall cut grading.
      • Brilliance: The light reflected back out through the top of a diamond. When a diamond is cut to the proper proportions, the level of Brilliance is maximised.

      Click here to download our diamond anatomy guide!