Cut Performance Registry · 21 July 2026
Eight cuts, one protocol. Every figure traced from the published geometry of the cut as it ships, ray-traced at each material's own refractive index, and scored against the same line: Tolkowsky's 1919 ideal. Born Clear, measured.
The registry
Sorted by Global within each material. The standard is marked. A lead of under half a point is not claimed as a win; a deficit is shown as a deficit, however small.
| Cut | Facets | Global | vs 1919 | Useful | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-Miliano | 201 | 93.45 | +1.80 | 95.1 | 82.9 | 1.83 | 92.7 | 98.9 | Ahead |
| BL-Cinderella | 193 | 93.05 | +1.40 | 93.1 | 85.4 | 4.42 | 93.1 | 98.6 | Ahead |
| BL-Rafaello | 193 | 92.84 | +1.19 | 93.9 | 80.2 | 4.94 | 96.9 | 98.6 | Ahead |
| Tolkowsky 1919 standard | 185 | 91.65 | 0.00 | 92.6 | 78.7 | 2.17 | 92.5 | 98.4 | Benchmark |
| Tolkowsky 73 | 73 | 89.85 | −1.80 | 92.9 | 78.3 | 1.91 | 92.2 | 80.3 | Behind |
| Brilliant 73 | 73 | 89.52 | −2.13 | 94.0 | 78.0 | 3.53 | 89.3 | 80.3 | Behind |
| Tolkowsky 57 | 57 | 88.61 | −3.04 | 92.3 | 78.8 | 1.88 | 90.4 | 71.8 | Behind |
| BL-M5 | 85 | 87.79 | −3.86 | 96.7 | 66.9 | 2.57 | 83.2 | 84.9 | Behind |
| Cut | Facets | Global | vs 1919 | Useful | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-M5 | 85 | 95.13 | +2.27 | 98.1 | 99.6 | 1.05 | 84.3 | 84.9 | Ahead |
| Tolkowsky 1919 standard | 185 | 92.86 | 0.00 | 86.1 | 97.2 | 7.46 | 94.0 | 98.4 | Benchmark |
| BL-Miliano | 201 | 92.61 | −0.25 | 86.5 | 92.8 | 7.32 | 96.8 | 98.9 | Behind |
| BL-Cinderella | 193 | 91.62 | −1.24 | 84.0 | 93.0 | 7.90 | 96.2 | 98.6 | Behind |
| Tolkowsky 73 | 73 | 91.04 | −1.82 | 86.0 | 97.2 | 7.40 | 94.1 | 80.3 | Behind |
| BL-Rafaello | 193 | 90.97 | −1.89 | 84.2 | 90.3 | 12.46 | 97.8 | 98.6 | Behind |
| Brilliant 73 | 73 | 89.93 | −2.93 | 86.5 | 95.8 | 7.44 | 88.0 | 80.3 | Behind |
| Tolkowsky 57 | 57 | 89.82 | −3.04 | 85.3 | 97.5 | 7.76 | 93.2 | 71.8 | Behind |
| Cut | Facets | Global | vs 1919 | Useful | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-Miliano | 201 | 95.34 | +0.75 | 97.4 | 90.5 | 1.16 | 89.8 | 98.9 | Slightly ahead |
| BL-Rafaello | 193 | 95.31 | +0.72 | 99.7 | 87.1 | 0.13 | 88.2 | 98.6 | Slightly ahead |
| BL-Cinderella | 193 | 95.01 | +0.42 | 97.8 | 91.6 | 0.51 | 85.2 | 98.6 | Level |
| Tolkowsky 1919 standard | 185 | 94.59 | 0.00 | 98.4 | 87.0 | 0.58 | 87.1 | 98.4 | Benchmark |
| Tolkowsky 73 | 73 | 92.77 | −1.82 | 98.4 | 86.8 | 0.60 | 87.4 | 80.3 | Behind |
| Brilliant 73 | 73 | 91.92 | −2.67 | 97.1 | 84.6 | 1.19 | 88.1 | 80.3 | Behind |
| Tolkowsky 57 | 57 | 91.77 | −2.82 | 98.0 | 86.8 | 0.51 | 87.1 | 71.8 | Behind |
| BL-M5 | 85 | 87.12 | −7.47 | 91.1 | 73.3 | 8.68 | 86.7 | 84.9 | Behind |
What the tables say
No cut beats the standard in all three materials. BL-Miliano leads in diamond (93.45) and cubic zirconia (95.34) and is the only cut at or ahead of the standard on every measured term in diamond, but in moissanite it finishes 0.25 behind.
BL-M5 is the moissanite specialist, at 95.13, with 99.6 fire and 1.05% leak, and the weakest cut in diamond and zirconia. It is cut for one material and shows it, in both directions.
BL-Rafaello holds the steadiest stone under tilt (96.9 in diamond, 97.8 in moissanite) and the cleanest light budget in zirconia, at 0.13% leak. BL-Cinderella carries the most fire of the house diamond cuts, at 85.4.
Tolkowsky 57 and 73 are reference stones, not house cuts: the 1919 ideal as a knife edge and with a faceted girdle. They are the control: the same design at 57, 73 and 185 facets. Across those three, useful light moves 0.6, fire 0.5 and leak 0.3, while scintillation climbs 71.8 → 80.3 → 98.4. Of the 3.04-point gap between Tolkowsky 57 and the standard, 2.66 (87% of it) is facet count alone. Read every other row against that: on this scale, facets are a cheap way to buy Global, which is exactly why the standard is set at 185 rather than 57.
The cuts
Method
Monte-Carlo on exact facet geometry: 3,200 rays face-up plus 2,200 at 20° tilt, cosine-weighted from a 7° near-vertical cone. Useful light exits through the crown within 64° of vertical.
0.34 useful + 0.20 fire + 0.16 tilt + 0.10 scintillation + 0.10 symmetry + 0.10 (100 − leak). Every cut scored against Tolkowsky's 1919 ideal, in the same material.
Engine estimates, ± 2 points, not lab-certified grades. Symmetry reads 100 for all eight because each cut is modelled from exact geometry rather than a cut stone, so it cancels out of every comparison on this site.
Four cuts are measured on a denser plane set than the live viewer draws, because the shader caps at 96 planes: Tolkowsky 1919 (185 measured, 64 rendered), BL-Miliano (201 / 64), BL-Rafaello (193 / 85) and BL-Cinderella (193 / 64). Every figure here comes from the measured set. The picture is coarser than the number.