Cut is often considered the most important of the four C’s because it determines the brilliance of the diamond. The more light reflected throughout the diamond, the greater the brilliance or sparkle.
Cut has three key components you should be aware of – Depth and Width, Symmetry, and Grade.
Depth And Width
If the cut is too shallow, light will leak out of the bottom of the diamond; too deep and light will reflect out of the side of the diamond. An “ideal cut” diamond is neither too shallow nor too deep, ensuring that no light will escape.
The symmetry of a diamond is defined by the alignment of its many facets (or surfaces) in relation to one another. An “ideal cut” diamond has all facets positioned in perfect geometric relation to the others, allowing light to bounce from facet to facet before returning through the top of the diamond back to your eyes.
Did You Know? A classic “round brilliant” cut includes a total of 58 perfectly aligned facets.
Leading gem laboratories such as the Gemological Institute of America (GIA) and the European Gemological Laboratory (EGL USA) grade diamonds according to the quality of their cut. They are graded on a scale from “poor” to “excellent”. Use the interactive scale below to further understand the differences in cut grades.
An ideal diamond will display the maximum amount of reflected light. Because symmetry plays such an important role, only “round” diamonds (as opposed to specialty shapes) can be graded as “excellent”
Very Good (Nearly “ideal”)
These diamonds reflect up to 90% of the light that enters them. They are exceptionally well-cut diamonds creating an exquisite stone. Good – Because these diamonds still reflect a good portion of the light that enters the stone, they make very attractive engagement rings.
Because these diamonds still reflect a good portion of the light that enters the stone, they make very attractive engagement rings.
These stones will reflect approximately 40% of the light that enters. While the size of the diamond can mean good value for money, the stone will lack high brilliance.
Although less brilliant than other diamonds and therefore not recommended for engagement rings, these still create a lovely effect in earrings and pendants and often represent excellent value.