Diamond Cut
Diamond Cut
Cut refers to a diamond’s light performance and is a measure of how effectively the diamond can return light to the viewer’s eye. In simple terms, it is a grading on how well the diamond is polished from the rough stone by measuring the refraction of light. This is arguably the most important attribute of the “4 c s of diamonds” as a well polished diamond will allow maximum brilliance, the fiery sparkle which has made diamonds so unique.
In a well cut diamond, light enters through the table (top surface) and travels to the pavillion where it is reflected from one side to another before reflecting back out of the table and to the observer’s eye (left image). That light which appears as a flashing rainbow of colors is called the “brilliance”, the fire which seems to come from the very heart of a diamond.
In a poorly cut diamond, the light enters through the table and once reaching the pavillion escapes either through the side (middle image) or through the bottom of the stone (right image) rather than reflecting back to the observer’s eye. This loss of light means less brilliance, hence a poor sparkle.
Because cut is an extremely important attribute, several grading standards have been implemented in order to determine the “cut grade” of a particular diamond. These grades are determined by the amount of light which a polished diamond reflects.
| Grade | Definition | |
| Ideal Cut | Reflects the maximum amount of light, hence brilliance is optimized. Such diamonds are highly sought after and would fetch a premium on the price. | |
| Very Good | Reflects almost the maximum amount of light. This loss of light is due to a trade-off in order to maximize the carat (weight) of the polished diamond. This grade is also highly sought after, but represents very good value as the price will be a little less. | |
| Good | Reflects most of the light. This loss of light is also a trade-off to achieve a critical polished weight. This is still a good option as the size of the diamond will be larger for a smaller outlay. | |
| Fair | Reflects some light. Typically, this would be a heavy included diamond with a lower color grade, hence making carat (weight) the principle attribute. This grade would probably not appeal to most people. | |
| Poor | Reflects low amount of light. All the attributes are sacrificed in order to maximize carat (weight). This will be a large diamond, but without that fire which makes them so special, probably not an ideal choice. |
Which cut grade should you choose?
- Selecting a diamond cut grade is really a matter of preference. Although difficult to discern with the naked eye, diamonds with higher cut grades do cost more due to the cutter’s skills. A highly graded diamond cut can appear to be larger than it actually is, due to the amount of fire and brilliance that it emits.
- Although not being “ideal cut”, diamonds with cut grades very good to good offer the best value for money. These grades are perfect for engagement rings and would usually delight the most discerning client.
