Short answers to common gem questions, each from our own measurements. We measure the light performance of our cuts in seven gemstones, and the face-up size of each shape. Each page shows the figures behind its answer.
- What is the best cut for moissanite?
- For the most light, the round brilliant is the best cut for moissanite in our ray traces. It returns the most light of the ten classic shapes: brilliance 86 out of 100.
- What is the best cut for a sapphire or a ruby?
- For the most light, the round brilliant is the best cut for sapphire and ruby in our ray traces. It returns the most light of the ten classic shapes: brilliance 94 out of 100.
- What is the best cut for an emerald?
- For the most light, the round brilliant is the best cut for emerald in our ray traces. It returns the most light of the ten classic shapes: brilliance 78 out of 100.
- What is the best cut for amethyst?
- For the most light, the round brilliant is the best cut for amethyst in our ray traces. It returns the most light of the ten classic shapes: brilliance 72 out of 100.
- What is the best cut for cubic zirconia?
- For the most light, the round brilliant is the best cut for cubic zirconia in our ray traces. It returns the most light of the ten classic shapes: brilliance 98 out of 100.
- Which diamond shape sparkles the most?
- By our scores for diamond, the round brilliant sparkles the most overall. It returns the most white light of the ten classic shapes: brilliance 93 out of 100.
- Which diamond shape looks biggest for its carat weight?
- 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.
- Oval or round diamond: which is better?
- In our models, a round brilliant returns far more light; an oval looks larger and scores higher for fire. In our ray traces of diamond, the round brilliant scores 93 for brilliance, the oval 47.
The light figures come from the Cut Performance Index, our open data, and the Cut Performance Wheel. The face-up figures come from our gemstone cut pages.