The Cut Of The Diamond

The term “cut” does not refer to the shape of the diamond, but rather it refers to the faceting proportions on the surface of the diamond. More than any other factor, the precise positioning of these facets determines the brilliance of the stone.

However, when a stone is faceted to maximize brilliance, it loses size. Conversely, when cut for size, it loses brilliance.

In a stone in which brilliance is maximized, the 57 (or 58) facets of the diamond are aligned perfectly with the 33 facets on the crown (top) functioning as windows, collecting light into the heart of the stone. The 24 or 25 facets on the pavilion (bottom) mirror the light back and forth creating the fire and brilliance.

The best diamonds are either Ideal or Premium cuts. Both Ideal and Premium cuts have a depth of 58.7% – 62.7%. The table of a Premium cut stone ranges from 58%-61% and the table of an Ideal cut stone is 53%-57%.

 

There are three different cuts to a diamond: deep, shallow and ideal/premium. A diamond that is has a depth of greater than 62.7% is considered a deep stone. At that point, when the light enters the diamond most of the light will “leak” out of the bottom of the stone and the stone loses its brilliance. It also may appear smaller than its actual size. A diamond that has a depth of less than 58.7% is considered shallow. At this point, even though the stone may appear larger, it will lose its brilliance because the light will “leak” out of the side of the diamond. In an ideal or premium cut diamond, 80% of the light will reflect back to the eye and 20% will reflect within the stone. At that point, the diamond will generate an internal mirror effect that allows for maximum brilliance.