Brillants

Brillants is a term used in gemology and jewelry to refer to diamonds cut in the brilliant style, most commonly the round brilliant cut. This term, which appears in English and French alike, denotes stones designed to maximize light return and sparkle through a specific facet pattern.

The round brilliant cut is the standard in modern diamond cutting. A typical round brilliant has 57 facets if the culet is present, or 58 facets if the culet is included. The facet arrangement and precise proportions are intended to optimize brilliance, fire, and scintillation by guiding light through the stone and back to the observer. While round brilliants dominate the market, the broader idea of a “brilliant cut” has been applied to other shapes in some catalogs, though with varying standards.

History and development: The concept of a brilliant-cut diamond emerged in earlier centuries and was refined in the 20th century. In 1919, Marcel Tolkowsky published a mathematical treatment of cut proportions that helped define the modern round brilliant’s angles and facet geometry, establishing a widely adopted benchmark for light performance. The term brillants thus anchors a tradition of diamond cuts engineered to maximize visual impact.

In use, buyers and professionals assess brillants with the four Cs, with cut quality being the most critical factor for light performance. The term can also appear in non-English contexts to describe diamonds cut in the brilliant style; the underlying principle is a facet pattern aimed at enhancing brilliancy.