Diamond Cut

What is Diamond Cut?

Diamond cut is one of the most important factors to consider when buying anengagement ring. A diamond cut is a style or design guide used when shaping a diamond for polishing. Cut does not refer to diamond shape but the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly impacts a diamond's brilliance – so, f a diamond is cut incorrectly, this can seriously affect the desirable ‘sparkle’ that is the staple feature of engagement rings and all diamond jewellery.

When choosing a diamond cut, two main factors need to be considered:

  • Refractive Index (RI) - the refractive index (RI) of a diamond is important to consider, which, at 2.417, is fairly high compared with that of most other gems. A diamond's RI is responsible for its brilliance - which is the amount of incident light that is reflected back to the viewer.

  • Dispersive power - also an important feature to consider is a diamond's dispersive power. This refers to the ability of the material to split white light into its component spectral colours - this is also relatively high, at 0.044. Those flashes of spectral colours that you see in a diamond, often known as 'fire in a diamond', are a function of this dispersion and are apparent only after cutting. Poorly cut diamonds are either too shallow or too deep, which causes the light to refract away from the diamond instead of refracting back from the top of the diamond.

Diamond cut refraction image

Available Cut Grades

  • Ideal
  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor

For the expert, perfectionist or diamond connoisseur, Ideal cut is the top characteristic to look out for when purchasing your diamond. Ideal cut diamonds are expensive - but they also get the best sparkle out of a diamond.

Polish and Symmetry

The polish and symmetry of diamond cut are both very important aspects.

  • Polish – this refers the smoothness of the diamond’s facets. Without adequate polish, the surface of the diamond facet can appear dulled, and may also create a blurred, or dulled, sparkle.
  • Symmetry – this refers to the alignment of the facets of the diamond. Poor symmetry can lead the light of the diamond to be misdirected, as it enters and exits the diamond.

Diamond Cut Buying Tips

Don’t underestimate the importance of diamond cuts. A well cut 0.90ct diamond, for example, could have the same width, and give out more brilliance and sparkle, as a poorly cut 1.00ct diamond. Ensure you buy only Good cut diamonds or above.

All diamonds used by Shining Diamonds are Good cut or above. However, if you have a specific requirement for a diamond cut please contact us for a customized quote.