The reflective dimensions of a diamond – its overall brilliance
The cut of a diamond refers to how well it reflects light, influencing its brilliance. This is the most important characteristic of the 4Cs. Whilst nature determines a rough diamond’s colour, clarity and carat weight, the cut of a diamond is dependent on the skills of the diamond cutter.
A diamond’s beauty is most influenced by how well it has been cut. When cut to exacting proportions, light will pass through the diamond and reflect back to the top, maximising its overall brilliance. Diamonds cut to exactly proportions are known as “ideal cut” diamonds. When a diamond is cut too “shallow”, light will leak through the bottom of the diamond, and when a diamond is cut too “deep”, light will escape through the side of the diamond, resulting in a loss of brilliance.
A skilled craftsman will release the “fire” and “scintillation” of a diamond. Light is naturally broken up into fragments of colours when it is passed through a prism. “Fire” refers to the density of the different colours that are seen within the diamond when light is illuminated through it. “Scintillation” refers to the shimmering effect the diamond generates when it is moved under a beam of light.
Diamonds are cut into certain proportions. The quality of a diamond is based on a grading system invented by Marcel Tolkowsky in 1919. He developed a grading system by measuring the brilliance of light that slices through the diamond and how it is related with its proportions.
The proportions of a diamond is based on following the guidelines:
Diamond cuts are graded based on their reflective qualities. We recommend excellent and very good cut diamonds. These are the top two grades that allow the most light to pass through, maximising the brilliance or sparkle of a diamond.
Excellent cut Very Good cut Good cut Fair cut Poor cut
Some gemologists go by other terminologies that help evaluate the quality of a diamond. Such terms that are used are AGS 000, Premium Cut, Excellent Ideal Cut and Tolkowsky Ideal Cut.