The Most Important C

Cut is considered by many to be the most important "C". Only when precisely calculated planes and angles are used, does the stone achieve its greatest possible beauty. A badly cut diamond, no matter how good its color and clarity will not match the fire and brilliance of a better-cut diamond with comparatively lower color and clarity.

View diamond parts in more detail.

Experts express differing opinions on the best table size (the diameter of the largest facet on the top of the stone) and the best depth for a diamond, because these factors alone are not sufficient to accurately judge its cut.

Other factors - crown angle, girdle thickness, pavilion depth-percentage (the ratio of depth to girdle diameter), culet size, polish and symmetry - also play a role in judging a diamond's overall cut quality.

Light Emission

A well-cut diamond will reflect most of the light back to the observer's eye. A poorly cut diamond will reflect only a small proportion of the light that enters it.

Diamond Cut guides

We at Gemnation use the following data tables as a guideline to understanding cut grades for brilliant diamonds. Round diamonds are the only shape that can be realistically evaluated with these measures. Other shapes, however, are also dependent on other factors and mere mathematical formulae will not necessarily determine a diamond's magnficence.

The data presented here is a composite of information from a multitude of sources, including definitions of the Tolkowsky Brilliant, Scandinavian Standard Brilliant, Eulitz Brilliant, and the AGS Laboratories' Ideal cut, together with our own gemologists' knowledge and experience.

Round

Princess

Radiant

Emerald

Oval

Pear

Marquise

Heart

Cushion

Trilliant

Asscher