3D model · 74 facets · 9.06 x 7.06 mm
The radiant: the outline of a step cut, with cropped corners, carrying a brilliant facet plan. It combines the clean shape of an emerald cut with the sparkle of a brilliant.
Drag to turn
The radiant: the outline of a step cut, with cropped corners, carrying a brilliant facet plan. It combines the clean shape of an emerald cut with the sparkle of a brilliant.
A strong choice for coloured stones, where the mixed facets help spread colour evenly.
Measured from the delivered model, not quoted from a standard.
The same geometry behaves differently in every material. Light that meets a pavilion facet at less than the stone's critical angle passes straight out of the back instead of reflecting, which shows face-up as a window. For each stone we measured how much of this model's pavilion, as seen face-down, is steeper than that angle, and what the model weighs at its reference size.
| Stone | Refractive index | Critical angle | Pavilion reflecting head-on light | Weight at this size | Verdict |
|---|---|---|---|---|---|
| Diamond | 2.417 | 24.4° | 96% | 2.00 ct | Minor windowing |
| Moissanite | 2.648 to 2.691 | 22.2° | 96% | 1.83 ct | Minor windowing |
| Cubic Zirconia | 2.15 to 2.18 | 27.7° | 96% | 3.30 ct | Minor windowing |
| Ruby | 1.762 to 1.770 | 34.6° | 38% | 2.27 ct | Steepen the pavilion |
| Sapphire | 1.762 to 1.770 | 34.6° | 38% | 2.27 ct | Steepen the pavilion |
| Emerald | 1.577 to 1.583 | 39.4° | 29% | 1.55 ct | Steepen the pavilion |
| Amethyst | 1.544 to 1.553 | 40.4° | 29% | 1.51 ct | Steepen the pavilion |
Head-on light, first reflection. A full light-return census is part of the Brilliani Labs engine and will come to this page.
Six formats: STEP (the exact faceted solid for CAD), 3DM for Rhino, STL and OBJ meshes, FBX for Blender, 3ds Max, Maya, Cinema 4D, Unity and Unreal, and GLB for the web and AR. All are in millimetres at real-world scale, with 74 planar facets.
The faceting design for the Radiant Cut is in preparation and will contain a GemCad file, a tier table and a printable diagram. The 3D files are available now.
We measured the pavilion of this model against the critical angle of each stone. In none of the seven stones does the whole pavilion reflect head-on light; in Ruby, Sapphire, Emerald, Amethyst, part of the pavilion lets light out of the back, so a steeper pavilion is advised.
The cutting file for the Radiant Cut is in preparation. Every cutting file we publish is checked facet by facet against its 3D model before it goes on sale.
The model measures 9.06 x 7.06 x 3.79 mm, which is 2.00 ct in diamond. The same size weighs 1.83 ct in moissanite, 3.30 ct in cubic zirconia, 2.27 ct in ruby, 2.27 ct in sapphire, 1.55 ct in emerald, 1.51 ct in amethyst. Scale it uniformly to any size: weight follows the cube of the size.
Yes. The mesh is watertight and manifold, with outward normals and no duplicate vertices, so it prints and casts without repair. Use the STEP file when you need the exact faceted solid in CAD.
The Radiant Cut as exact geometry: 74 planar facets, real-world scale, ready for CAD, rendering, printing and casting.
The faceting design for the Radiant Cut is in preparation. It will include the GemCad file, the tier table and a printable diagram.
Want to know when checkout opens? Email us and we will tell you once.