A 3D model of a gemstone is a digital solid of its facets for CAD, rendering, printing or games. An exact model has flat facets, sharp edges and a closed, watertight surface at real size.
In more detail
A model made to look good is not always made to be cut. Rounded, smoothed or open models cannot be measured. Use a cutting file to cut a stone, and a 3D model to set, render or print it.
How we measure it
Our models are in millimeters, with the table facing +Y and the girdle plane through the origin. They come as STEP, 3DM, STL, OBJ, FBX and GLB. We build them from the same geometry as the cutting files.
Related terms
- Mesh: A mesh describes a 3D surface as many small flat triangles joined at their edges. STL, OBJ, FBX and GLB files store a mesh.
- STEP file: STEP is a standard CAD format that stores an exact solid, with each facet as a true plane. CAD programs such as FreeCAD, Rhino and Fusion open it to measure a stone and design a setting.
- Watertight: A watertight model is a closed surface with no holes, so it encloses a solid. In a closed mesh, exactly two triangles share every edge.
- Convex: A convex stone has no inward corners: a straight line between any two points inside it stays inside. Most cut stones are convex; a heart, with its notch, is not.
- Cutting file: A cutting file is a faceting design: every facet's angle and index, in cutting order, for a faceting machine. It tells a faceter how to cut the stone.