Diamond education

Diamond Cut

A well cut diamond sparkles more, posing a magnificent display of three key attributes - Brightness, Fire and Scintillation.

A beautifully finished diamond is dazzling, with every facet displaying the craftsman’s skill and care. When a diamond interacts with light, every angle and every facet affects the amount of light returned to the eye. This is what gives it its face-up appearance. A diamond's proportions determine how light performs when it enters the diamond. If light enters through the crown and goes out through the pavilion, the diamond will look dark and unattractive. Diamonds with different proportions and good polish make better use of the light, and will be bright, colorful, and scintillating. A well-cut diamond displays the beauty consumers expect to see in a diamond.

A beautiful diamond looks the way it does because of three optical effects: white light reflections called brightness, flashes of color called fire, and areas of light and dark called scintillation. Pattern is the relative size, arrangement, and contrast of bright and dark areas that result from a diamond’s internal and external reflections. There must be enough contrast between the bright and dark areas to give the pattern a crisp, sharp look.

cut_scale

The diamond industry has long known that some proportion combinations make light perform better than others. In recent years, however, scientists and researchers in GIA’s Research Department and the GIA Laboratory have shown that there are many variations and combinations of proportions that will maximize brilliance and fire in round brilliant cut diamonds.

As a general rule, the higher the cut grade, the brighter the diamond. Under fluorescent lighting, these diamonds (left to right) display high, moderate, and low brightness.

The term "cut" also can describe a fashioned diamond's shape. Shapes other than the standard round brilliant are called fancy cuts. They're sometimes called fancy shapes or fancies. Fancy shapes also have names of their own, based on their shapes. The best known are the marquise, princess, pear, oval, heart, and emerald cut.

A well cut diamond sparkles more, posing a magnificent display of three key attributes - Brightness, Fire and Scintillation.

diamond_cutcut_scale

Diamonds with fine proportions, symmetry and polish optimise their interaction with light and have increased brightness, fire and scintillation.

img_perfect_cut img_perfect_cut