Face-up: the crown facets, drawn from the model's own edges.Profile: 61.0% total depth.
Light Return map of the Hexagon Cut in diamond. A computed render of the model's geometry, not a photograph.
The Hexagon Cut in seven gemstones
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. The pavilion mains of this design sit at 29.3°. As a rule of thumb a round design needs about 43.5° in amethyst for head-on light to reflect twice before it leaves the crown, so the mains are worth steepening for diamond, moissanite, cubic zirconia, ruby, sapphire, emerald, amethyst.
Head-on light, first reflection. A full light-return census is part of the Brilliani Labs engine and will come to this page.
Hexagon Cut: questions
What files come with the Hexagon Cut 3D model?
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 37 planar facets.
Is there a faceting diagram for the Hexagon Cut?
Yes. The cutting files contain a GemCad .asc design (31 + 6 girdles = 37 facets, 96 index, 6-fold mirror-image symmetry), a tier table with angles, indices and cutting order in CSV, and a printable faceting diagram.
Does the Hexagon Cut work in sapphire, emerald or amethyst?
We measured the pavilion of this model against the critical angle of each stone. In Diamond, Moissanite, Cubic Zirconia, the whole pavilion reflects 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 pavilion mains of this design sit at 29.3°. As a rule of thumb a round design needs about 43.5° in amethyst for head-on light to reflect twice before it leaves the crown, so the mains are worth steepening for diamond, moissanite, cubic zirconia, ruby, sapphire, emerald, amethyst.
How accurate is the Hexagon Cut cutting file?
We check it facet by facet against the 3D model it was written from. Every crown and pavilion facet within 0.003° of the 3D model (average 0.002°). The angles are the ones you set on the machine; the 3D model is the same stone you render or set.
How big is the Hexagon Cut model, and what does it weigh?
The model measures 7.93 x 6.87 x 4.19 mm, which is 2.00 ct in diamond. The same size weighs 1.39 ct in moissanite, 2.50 ct in cubic zirconia, 1.73 ct in ruby, 1.73 ct in sapphire, 1.17 ct in emerald, 1.14 ct in amethyst. Scale it uniformly to any size: weight follows the cube of the size.
Can I 3D print or cast the Hexagon Cut model?
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.