A diamond´scut makes the difference. It is the cut that gives a diamond his desired shape,unique brilliance and fascinating fire. In fact, this brilliance and fire coststhe diamond 60% of its original raw material weight. The better the cut, themore light is returned through the table which maximizes the light performance.Cut is the most important C of all 4 and at the same time the most interesting,too: What really makes the difference is man´s work, expertise and skill whichall together only unveils the beautiful appearance of nature´s most uniqueproduct. It is the human factor that lights the fire in the diamond, creates itssparkle and –by doing so- brings the diamond to life!
There are 5 cut grades ranging from poor to excellent. The cut grade refers to the proportions and finish (that is, symmetry and polish) of a round brilliant cut. Having a direct impact on brilliance and fire the cut essentially influences the beauty of a diamond. A diamonds cut essentially describes how light interacts with the diamond. Compare the following illustration of how light travels within the diamond with varying proportions:
"Too shallow" "Ideal" "Too deep"
A diamond´s light performance consists of three main factors:
Brilliance
This prominent diamond feature gives the round brilliant cut its name. Brilliance essentially describes the amount of light that is reflected within the stone and thrown back to the eye of the spectator. The better the proportions and arrangement of the facets, the more light can be returned.
Scintillation
Scintillation is what is seen as black and white patterns of sparkling light caused by facet reflection within the diamond.
Fire
Fire refers to the sparkling rainbow colors that are visible when white light is separated into its spectral colors.
The varying parameters within a cut grade are less a variation in quality as more a matter of taste. An example is the table size:
The bigger the table, the higher the brilliance because more light can be returned through the table. The smaller the table, the more fire the diamond has since more light can be separated into the rainbow colors. At the end of the day it is a matter of taste. Traditionally in Europe people tend to prefer larger tables, whereas in the United States smaller tables are considered more desirable.
| Cut Grade | Explanation |
| Excellent | Almost all light that enters the diamond is also reflected. The proportions and facet alignment guarantee a maximum in light performance. |
| Very good | Nearly as much light as in an excellent cut is thrown back to the eye of the spectator. The cut grade "very good" stands for a well cut diamond whose proportions create a great sparkle and brilliance. |
| Good | A good cut reflects most light that enters, yet diamonds with this cut grade are sold for a discount. |
| Fair | Even though a diamond with a fair cut is still a diamond and a precious gem stone afterall, however, the lacking sparkle might compromize its beauty. |
| Poor | Poorly cut diamonds are either very deep or very shallow. While very shallow diamonds might appear bigger in size when viewed from above, poorly cut diamonds show a poor light performance and return very little light due to misalignment in facets and proportions. |
Brilliance
Scintillation
Fire