The 5 C’s, Cut

Cut Grading

Diamond Cut or Proportion Grade
Diamond Cut or Proportion Grade

The cut of a Diamond is the only property, which is totally dependent on man. Cut refers not only to the shape and style of the diamond, but its proportions, symmetry, and finish or make.


Polished Diamond Proportions
Polished Diamond Proportions

Proportions and angles influence the internal reflection of light as well as the dispersion of light leaving the diamond. This determines the brilliance and fire (brightness and sparkle) of the diamond, and ultimately it’s perceived beauty.

Cut therefore, is actually one of the most important aspects to consider when choosing your diamond. A diamond can be cut for maximum weight recovery or maximum brilliance and beauty. Invariably one is traded of at the expense of the other. Although poor makes sell at a discount in the trade, realistically the unsuspecting retail customer will pay the same price regardless of make.

For Round brilliants there are several so called optimum cuts all with slightly different proportions. These are based on scientific formulas to maximize the return of light from the diamond. Ultimately taste and preference for the overall appearance determine the buyer’s choice.

A Round Brilliant Shape diamond typically has 57 or 58 facets, each of which plays an important role in how the diamond reflects light and creates its characteristic brilliance and sparkle. Here are the main facets on a round brilliant cut diamond:

Table – This is the largest and flat facet on the top of the diamond. It is the primary facet that allows light to enter and exit the diamond.

Crown – The crown includes several facets that run from the table down to the girdle of the diamond. These facets serve to refract and reflect the light that enters the diamond, enhancing its brilliance and fire.

Pavilion – The pavilion is the bottom half of the diamond, and includes several facets that run from the girdle down to the culet. These facets serve to reflect the light that enters the diamond back up towards the crown, maximizing the diamond’s brilliance.

Girdle – The girdle is the widest part of the diamond, located where the crown and pavilion meet. It serves as the diamond’s perimeter and holds the facets in place.

Culet – The culet is a small facet at the bottom of the diamond, where the pavilion facets meet. It is usually very small or non-existent and is there to prevent chipping and breaking of the diamond.

All these facets are carefully arranged and cut to maximize the amount of light that enters and exits the diamond, creating the characteristic brilliance and fire for which diamonds are renowned. The quality of the cut, along with the other 4 Cs (carat weight, colour, and clarity), determine a diamond’s overall beauty and value.