Product was successfully added to your shopping cart.

diamond cut explained

Diamond cuts

While the other 4 c's - carat, color , clarity affect the diamonds overall value, it is the diamond cut that determines the stone's facets, proportions and its ability to reflect light. An expertly cut diamond will have a high brilliance or sparkle. Even if the other characteristics are near perfect a poor cut can result in a dull , shineless diamond. The beauty of a diamond depends more on cut than on any other factor.

Cut does not only refer to the diamonds shape but to the proportions, symmetry and polish of the diamond. 


The diamond cut has three primary effects on the diamonds appearance:

      • brilliance or brightness of the diamond
      • fire or the dispersion of the light into colors
      • sparkle when the diamond is moved.


When light shines on a diamond approximately 20% immediately reflects off the surface. The rest enter the diamond and depending on the cut is reflected back to the surface and creates the brilliance, fire or sparkle. With poorly cut diamonds the lights leaves the diamond at the bottom.


Examples of poorly cut diamonds

diamond cutdiamond cut

Example of a well cut diamond

diamond cut

When diamonds are cut there is a high pressure to maintain as much carat weight from the rough stone as possible. Appearance is often sacrificed for weight. This is why the cut grade is important as it allows the buyer to identify the stones that were cut fair to poor to preserve or even gain carat weight.


Diamond cut grade

The "Cut" of the "4-Cs" is the most difficult part for a customer to judge when selecting a good diamond. This is because some certificates will not show the critical measurements influencing cut (such as the pavilion angle and crown angle) and will not provide a subjective ranking of how good the cut was. The other 3-Cs can be ranked simply by the rating in each category. Below you will find the different rating used to determine the cut of a diamond.


Excellent     The best diamond cut. Maximum fire and brilliance. Reflects nearly all of the light that enters the diamond, creating exceptional sparkle and life.

Very Good   Properly reflects most of the light that enters the diamond, producing superior fire and brilliance. Under normal lighting conditions, appears very similar to Excellent Cut, but for a lower price.

Good           Reflects a majority of the light that enters the diamond, for an above average appearance. An excellent value compared to higher cut grades.

Fair             Allows much of the light entering the diamond to escape from the sides or bottom, reducing perceived fire and brilliance. More acceptable in diamonds of less than .75 carats, where differences in sparkle are more difficult to perceive.

Poor           Allows most of the light entering the diamond to escape from the sides or bottom. The diamond may appear noticeably dull and lifeless, even to an untrained eye.


Diamond cut : Polish and symmetry

Polish and symmetry are two important aspects of the diamond cut. The polish describes the smoothness of the diamond's facets, and the symmetry refers to alignment of the facets. With poor polish, the surface of a facet can become dull, and may create blurred or dulled sparkle. It may also constantly look like it needs to be cleaned. With poor symmetry, light can be misdirected as it enters and exits the diamond.


The bottom line

 While carat determines the weight of your diamond it is actually the cut that will determine the size of the diamond. 


Diamond cut : our advice to find a high quality diamond

We at recommend only Very Good and Excellent Cut stones. These parameters will ensure that your Diamond has an optimal Brilliance and Sparkle.  If however, you feel that this parameter is not so important to you, we can always offer you 'lesser' cut diamonds at more interesting prices.

search our loose diamonds



Diamond cut : a GIA education video


Further diamond education

Our diamond education pages help you to understand the 4 C's of diamond quality so yo can choose your next diamond wisely.

Learn more about : the 4 C's of diamond quality - The different diamond shapes - Diamond certification



Learn more and save money buying diamonds online. Get your FREE guide today.