The modern brilliant cut diamonds were developed in early to mid 20th century and have variations in bezel facet length (longer in the early modern brilliant cut diamonds than in the later modern brilliant cut diamonds) and in the position of the pavilion main facets, which extend longer in the later modern brilliants than in the early modern brilliants.
Diamond shapes in this category include: oval, pear, marquise, heart, trillian and various other oddly-shaped side stones, such as the kite and moon-shaped, side- stone diamonds. This is the most populous category of fancy diamond cuts, because the standard round brilliant can be effectively modified into a wide range of shapes.
The modified brilliant cut diamond includes the round brilliant within its parameters. And while the round brilliant is not considered a fancy cut, there are many subcategory fancy shapes resulting from the brilliant cut.
Other Shapes That Have Evolved
Diamond shapes that emerge from the brilliant cut diamonds are variations on the round brilliant diamond.
The brilliant cut diamonds are marked by the 58-facet form. As the name implies, this cut creates diamond shapes that are faceted for maximum brilliance and fire.
Because their facet counts and facet arrangements are the same, modified brilliants also look the most like round brilliants in terms of brilliance and fire interplay and, therefore, are in general the most salable.
Most commonly encountered modified brilliant cut diamonds include the marquise or navette (French for “little boat”), which resemble the hull of a sailboat); heart; triangular trillion (also trillian or trilliant); an oval; and the pear or drop cuts.
Oval-shaped diamonds were created and introduced by Lazare Kaplan in the 1960s and have 56 facets.
The weight of such diamonds is estimated by measuring the length and width of the stone. A ratio of 1.33 to 1.66 provides a good traditional range of oval shaped diamonds.
Pear shaped diamonds are known as the teardrop shape because of their striking resemblance and are considered to be a hybrid between the marquise-cut and the round brilliant diamond. One end of the stone is rounded, while the other end is pointed.
While length to width ratios between 1.45 and 1.75 are most common in pear shape diamonds to achieve the ideal pear shape, they vary in length and width ratios. With modern cutting technology the development of increasingly complex and unthinkable shapes, such as stars and butterflies, have emerged.
Although proportions are mostly a matter of personal preference, because of their sharp terminations and a diamond’s relative fragility, these cuts are more prone to breaking and, therefore, are oftentimes more difficult to insure.
Other Forms Of Brilliant Cut Diamonds
Other older modified brilliant cuts of uncertain age, no longer widely used, but historically noteworthy are the king cut and magna cut, both developed by New York firms. The former cut possesses 86 facets and 12-fold symmetry and the latter, 102 facets and 10-fold symmetry.
The high-light cut, developed by Belgian cutter M. Westreich, with 16 additional facets divided equally between the crown and pavilion; and the princess 144, introduced in the 1960s, with 144 facets and 8-fold symmetry.
Not to be confused with the mixed Princess diamond cut, the Princess 144 facet cut makes for a lively stone with good scintillation. The extra facets are cut under the girdle rather than subdivided. The extra care required for these sub-girdle facets definitely benefits the finished diamond by mitigating the girdle irregularity and bearding (hairline fracturing).
An increased understanding of light dynamics and diamond cutting has helped many companies to develop new, modified, round brilliant cut diamonds. When designed correctly, these extra diamond facets of the modified round brilliant can enhance the overall beauty of a diamond, such as in 91 facet diamonds.
The Dutch firm Gassan has patented a new brilliant cut with 121 facets.
All of these diamond cuts are round in outline and modify the standard round brilliant diamond, by adding more facets and changing the symmetry of the diamond, either by dividing the standard facets or by placing new ones in different arrangements such as in side setting for diamond engagement rings, necklaces, earrings or pendants.