Diamond Cut
The term cut refers to the facets, and their proportions, on the surface of a diamond. Ideal Cut Diamonds have explicitly defined relationships between the table, the crown, the pavilion and the girdle of every stone.
Carat weight is wrongly thought by many to be the most important factor in deciding the value of a diamond. Unfortunately, this misconception has led some diamond cutters to take advantage of the first-time buyer. For example, some diamond cutters will leave an excessively thick girdle around the stone, increasing the diamond’s carat weight.
This practice harms the stone, considerably impairing the diamond’s beauty and brilliance.
The Most Frequent Mistakes In Cut
AN INCORRECT NUMBER OF FACETS: A round brilliant diamond has 57 facets. Experience has shown that this is the most effective number to optimize the reflection of the light. Having a greater number of facets does not produce a diamond of higher quality. In fact, increasing the number of facets reduces the brilliance.
EXCESSIVE WEIGHT: Contrary to popular belief, excessive weight reduces aesthetic appeal. Since the number of carats is often considered as the most important criterion with regard to a diamond’s value, one common trick is to leave too thick a girdle. This gives the diamond more carats and therefore a higher price. Unfortunately, it also considerably diminishes the brilliance and beauty.
THE “LARGE ANGLE” EFFECT: When a diamond is given a flat cut and too large a table, the stone is dulled. Even worse, it produces an unattractive large angle effect across the crown.
THE “NAIL HEAD” EFFECT: If the cut of the diamond is too deep, a dark nail head may appear in the center of the stone.
Diamond Shape
Cut shouldn’t be confused with "shape." Shape refers to the general outward appearance of the diamond, (such as round, emerald, or pear).