A cut grade is given only to a round brilliant diamond. Being the most sought-after diamond shape, GIA has spent decades developing a system to grade the cut quality of round diamonds. The term diamond cut refers not to a diamond’s shape, but the balance of proportions achieved by the diamond cutter.
While everyone has their favourite combination of the 4 Cs – colour, clarity, cut, and carat weight — cut has the greatest influence over a diamond’s brilliance, determining what we call “sparkle.”
A diamond’s cut is measured using an international grading system developed by the Gemological Institute of America (GIA). Cut grades range from Excellent to Poor. Very good and excellent cut grades guarantee the greatest brilliance and fire.
The cut grade combines three different types of reflections:
- Brilliance: The brightness created by the combination of white light reflections inside and on the surface of the stone.
- Fire: The spread of white light into all the colours of the spectrum.
- Scintillation: The flashes of light and dark, and the sparkle a diamond emits when the light is moved.
For the greatest brilliance and fire, we recommend (and only offer) ‘very good’ and ‘excellent’ cut grades for round brilliant diamonds. GIA spent decades refining and developing a cut grading system for round brilliant diamonds which shows the significance of the round brilliant.
Our consultants are available to help you to better understand the importance of a diamond’s cut and this affects the visual aspects of your diamond engagement ring‘s design.