A diamond’s cut will most certainly influence its fire (rainbow colors that flash from within) and brilliance (sparkle and radiant), as well as its perceived size, depth and width. Different cuts reflect light in different angles. A diamond must be cut in a geometrically precise manner to maximize its brilliance. A master cutter allows the diamond to be cut in such a way that permits the maximum reflection of light that enters the diamond back to the top of the diamond. A typical brilliant cut round diamond is cut with 58 facets, 33 on the crown and 25 on the pavilion. On a well-proportioned stone, these facets will be uniform and symmetrical. If they are not, the diamond’s ability to refract and reflect light will suffer.

To grade a diamond cut, we normally look at different aspects such as the shape, symmetry, polishing, angle and proportion of the diamond.

Cut Grading 1- 10

Ideal Cut — Superior craftsmanship in the diamond cutting process. All cut quality factors are at the highest possible levels, and they make the maximum contribution to the diamond’s beauty and value.

1 Cut — This describes a very high level of expertise on the part of the cutter. There are very slight variations in one or more of the diamond cut quality factors, but these can be detected only by computer analysis or by a trained and certified diamond grader working under controlled conditions.

2 Cut — This describes a high level of diamond cutting expertise. There are slight variations in one or more diamond cut quality factors that can be detected by computer analysis or by a trained diamond grader.

3 & 4 Cut — Minor variations in one or more diamond cut quality factors can be detected by computer analysis or by a trained diamond grader. These variations may have a slight effect on the diamond’s beauty, durability, or size appearance. You may notice differences in appearance if careful side-by-side comparisons are made to diamonds of higher diamond cut grades.

5 to 7 Cut — Sizable variations in one or more diamond cut quality factors can be detected by computer analysis or by a trained AGS Laboratories diamond grader. These variations have little effect (in grade 5) to a noticeable effect (in grade 7) on the diamond’s beauty, durability, or size appearance. You are likely to notice a less attractive appearance in diamonds that grade 5, 6, or 7 due to light performance.

8 to 10 Cut — Major variations in one or more diamond cut quality factors have significant (8) to serious (10) negative effects on the diamond’s beauty, durability, or size appearance. You almost certainly will notice poor light performance in many diamonds in these diamond cut grades.