Cut registry › House cuts
Cut registry · 5 house designs
Five designs, published in full.
These are the facet designs Brilliani Labs drew itself. Each is measured on the same census as every other cut on this site, against a standard we did not get to choose, and each one is published term by term rather than as a single score.
The short version
A house cut is a facet plan, not a shape. All five are round brilliants, so what separates them from each other, and from Tolkowsky’s 1919 ideal, is how the facets are arranged rather than the outline they sit in.
BL-Miliano leads in diamond at 93.28 Global, +4.68 against the standard and the widest margin in the registry. BL-M5 leads in moissanite at 95.13, because a cut is solved against a refractive index and moissanite’s is not diamond’s. No single design wins everywhere.
A large share of any modern cut’s margin is facet count, and we say so on every page. Scintillation on this engine is a pure function of the number of facets that actually reach the surface, so a cut carrying 145 or 201 of them banks roughly 2.4 to 2.7 points against a 57-facet standard before its optics are assessed at all. Subtract that, and what is left is the part the design earned.
The figures
Global is the weighted score used across this site: 0.34 useful light, 0.20 fire, 0.16 tilt, 0.10 scintillation, 0.10 symmetry, 0.10 low leak. A lead under half a point is not claimed as a win; a deficit is shown as a deficit, however small.
| Cut | Facets | Global | vs T57 | Brilliance | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-Miliano | 201 | 93.28 | +4.68 | 94.8 | 83.0 | 2.25 | 92.5 | 98.9 | Ahead |
| BL-Rafaello | 145 | 92.57 | +3.97 | 93.9 | 80.2 | 4.94 | 96.9 | 96.0 | Ahead |
| BL-Girandola | 93 | 91.92 | +3.32 | 93.1 | 85.4 | 4.42 | 93.1 | 87.3 | Ahead |
| BL-Anteros | 73 | 88.39 | −0.22 | 94.6 | 74.2 | 2.30 | 84.9 | 80.3 | Behind |
| BL-M5 | 85 | 87.79 | −0.81 | 96.7 | 66.9 | 2.57 | 83.2 | 84.9 | Behind |
| T57 standard | 57 | 88.61 | 0.00 | 92.3 | 78.8 | 1.88 | 90.4 | 71.8 |
| Cut | Facets | Global | vs T57 | Brilliance | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-Miliano | 201 | 92.31 | +2.49 | 86.6 | 92.5 | 7.58 | 95.1 | 98.9 | Ahead |
| BL-Rafaello | 145 | 90.71 | +0.89 | 84.2 | 90.3 | 12.46 | 97.8 | 96.0 | Ahead |
| BL-Girandola | 93 | 90.49 | +0.67 | 84.0 | 93.0 | 7.90 | 96.2 | 87.3 | Ahead |
| BL-Anteros | 73 | 90.93 | +1.11 | 91.9 | 91.1 | 2.76 | 85.7 | 80.3 | Ahead |
| BL-M5 | 85 | 95.13 | +5.31 | 98.1 | 99.6 | 1.05 | 84.3 | 84.9 | Ahead |
| T57 standard | 57 | 89.82 | 0.00 | 85.3 | 97.5 | 7.76 | 93.2 | 71.8 |
| Cut | Facets | Global | vs T57 | Brilliance | Fire | Leak | Tilt | Scint. | Verdict |
|---|---|---|---|---|---|---|---|---|---|
| BL-Miliano | 201 | 95.06 | +3.28 | 97.1 | 89.9 | 1.17 | 89.2 | 98.9 | Ahead |
| BL-Rafaello | 145 | 95.05 | +3.28 | 99.7 | 87.1 | 0.13 | 88.2 | 96.0 | Ahead |
| BL-Girandola | 93 | 93.88 | +2.10 | 97.8 | 91.6 | 0.51 | 85.2 | 87.3 | Ahead |
| BL-Anteros | 73 | 88.98 | −2.79 | 92.3 | 81.7 | 6.55 | 86.9 | 80.3 | Behind |
| BL-M5 | 85 | 87.12 | −4.65 | 91.1 | 73.3 | 8.68 | 86.7 | 84.9 | Behind |
| T57 standard | 57 | 91.77 | 0.00 | 98.0 | 86.8 | 0.51 | 87.1 | 71.8 |
The five
A name that misleads
It carries the BL prefix and it is not one of these five. BL-Vitruvio keeps Tolkowsky’s 1919 angles unchanged and belongs to the T-series, where it is the 185-facet member.
It was renamed from T185 in July 2026 because it no longer follows the T-plus-facet-count convention. The name moved. The design did not.
A different question
Everything on this page is a round brilliant. If you are choosing an outline rather than a facet plan, that is a separate question with its own section: the popular jewellery cuts, measured on this same protocol.
The short version there is that no fancy shape beats a round brilliant for light return, and the useful question is what each shape costs you.
Questions
A house cut is a facet design Brilliani Labs developed itself, rather than a shape or a trade standard. There are five: BL-Miliano, BL-Rafaello, BL-Girandola, BL-Anteros and BL-M5. Each is measured on the same ray census as every other cut on this site and published term by term against Tolkowsky's 1919 ideal round brilliant, so the claim can be checked rather than taken on trust.
In diamond, BL-Miliano at 93.28 Global, +4.68 against the standard, the widest margin in the registry. In moissanite the order changes and BL-M5 leads at 95.13. A cut is solved against a refractive index, so no single design leads in every material.
A large part of it, and we publish that rather than hide it. Scintillation on this engine is a pure function of the number of facets that reach the surface, so a cut carrying 145 or 201 facets banks roughly 2.4 to 2.7 points against a 57-facet standard before its optics are assessed at all. Subtract that and what remains is the part the designer actually earned. Every house-cut page shows the split term by term.
No, despite the BL name. BL-Vitruvio carries Tolkowsky's 1919 angles unchanged and belongs to the T-series, where it is the 185-facet member. It was renamed from T185 in July 2026 because it no longer follows the T-plus-facet-count naming, but its design lineage did not change.
These are published cut designs measured as geometry, not stock. If you want to see one rendered and turned in real time, every house cut is available in the Index and in Compare. For anything beyond that, use the contact page.
No. They are engine measurements of a design, accurate to roughly two points, produced by Monte Carlo ray tracing on exact facet geometry at a fixed seed. They deliberately exclude the workshop: a finished stone's polish and symmetry deviation belong to the cutter and the rough, not to the design. They are not a substitute for a GIA, IGI or AGS report.
Because we did not get to choose it. Every benchmark on a maker's own website has the same problem, that the maker picked it. Marcel Tolkowsky published the round brilliant's proportions in Diamond Design in 1919, the trade adopted them, and they are still the reference the industry argues about. The cost of that choice is that the bar is not high, which is why every margin here is published term by term rather than as one score.
A shape is the outline of the stone, such as oval, cushion or emerald. A cut design is the facet plan inside that outline. All five house cuts are round brilliants, so they differ from each other in facet plan rather than in silhouette. The popular shapes are measured separately in the jewellery cuts section.
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, at a fixed seed so every figure reproduces exactly rather than approximately.
T57, Tolkowsky’s 1919 ideal as specified: 57 facets, 53% table, 34.5° crown, 40.75° pavilion, knife-edge girdle, 59.2% depth. Read what he actually calculated.
The workshop. These measure a design, not a finished stone: polish and symmetry deviation belong to the cutter and the rough. Symmetry reads 100 for every cut here because each is modelled from exact geometry, so it cancels out of every comparison.
Engine estimates, roughly ±2 points. Not a laboratory cut grade and not a substitute for a GIA, IGI or AGS report.
Back to the full registry, across to the jewellery cuts, or open any of these in the Index.