Thanks to the mathematician Marcel Tolkowsky, we know exactly which angles optimize the diamond's efficiency as a refractive vessel of light. An Ideal cut falls within the strict mathematical proportions illustrated above. Because symmetry is required for maximum light reflection, only round diamonds may be graded as ideal cuts. Very good cuts are considered exceptionally proportioned, investment quality stones. A Good cut describes a well-proportioned stone that reflects back a good proportion of light.
Good cuts are well suited as jewelry stones.
A Fair cut diamond has been cut to maximize the weight of the original stone, at the expense of fire and brilliance. A Poor cut diamond appears lifeless to the eye. Poor cut stones are not recommended for fine jewelry, and we do not offer poorly cut diamonds for sale to our customers. These proportions are detailed on the diamond certificate. When evaluating a diamond's cut, you should also check the diamond's specifications against the following table to determine whether the polish, symmetry, girdle, and culet of the diamond fall within acceptable standards.