The marquise looks biggest for its carat weight in our models. Its face-up area is 21% larger than that of a round brilliant of the same weight. The radiant (+18%) and the pear (+15%) also have a larger face-up area. The trilliant (−7%) and the cushion (−3%) have a smaller one. In our traces of diamond, the marquise also leaks more light: 17%, against 2% for the round brilliant.
| Shape | Face-up size | Light leakage in diamond |
|---|---|---|
| Marquise | 121% | 17% |
| Radiant | 118% | 41% |
| Pear | 115% | 22% |
| Oval | 108% | 27% |
| Emerald cut | 105% | 25% |
| Asscher | 102% | 11% |
| Princess | 101% | 18% |
| Round brilliant | 100% | 2% |
| Cushion | 97% | 9% |
| Trilliant | 93% | 11% |
Why
Face-up size depends on the outline and the depth. A long, shallow stone spreads the same weight over a larger area. These percentages hold in every gemstone, because density changes the weight of every shape by the same factor.
In our traces, shapes that face up larger often lose more light through the back. This leakage is one cause of the dark bow-tie in a long stone.
Compare any two cuts in the Cut Performance Wheel, or turn them in light in the 3D Gemstone Simulator.