The round brilliant cut of polished diamond, which contains 58 facets and is intended to maximize the amount of light emitted from the top of the stone, was invented by Marcel Tolkowsky in 1919. Though the brilliant cut has specific criteria, there are also variations on it.
The top view of the brilliant cut includes 8 star facets, 8 kite facets and 16 upper girdle facets, while the bottom view of the stone has 16 lower girdle facets and 8 pavilion main facets.
The cut may optionally include a culet, a small round face on the bottom of the diamond, instead of coming to a point. The girdles of brilliant cuts may have different facet counts: 43, 64, 80 or 96.
A phenomenon observed in some brilliant round cut is the “hearts and arrows”. If the stone is cut with precise symmetry, when viewed from the top one may see arrow patterns, while when viewed from the bottom, heart shapes may be visible. The visibility of the hearts and arrows are not necessarily positively correlated with the amount of brilliance.
