Two ways into the same geometry. The 3D Gemstone Simulator shows you a stone. The Brightness & Tilt Analysis measures how it handles light. Both work from the same measured models as the files we sell.
-
3D Gemstone Simulator
Build a digital stone and read its 3D gemstone report as you go: 35 cuts in seven gemstones, the
four Cs, ten kinds of light.
Open the simulator
-
Brightness & Tilt Analysis
See how much light a cut returns face-up, and how that holds as the stone tilts.
Open the analysis
Everything in one place
The pieces have always existed, just never together. One site has a beautiful viewer you can’t adjust. Another explains the four Cs clearly but never shows them to you. GemCad, GemRay, GemCut Studio and FreeCAD are superb tools, built for people who already know what they’re doing.
Our simulator brings those worlds into one place. Change the cut, the material, the colour or the lighting, and watch the stone respond. There is no wrong setting and nothing to break. If a choice confuses you, choose something else and you’re back on solid ground.
The 3D Gemstone Simulator
Pick any of our 35 cuts, choose one of seven gemstones, and set its carat, colour and clarity in the report itself. The stone is drawn live from the same geometry as our 3D files and cutting files, under ten kinds of light from a grading lamp to a camera flash. Turn on the Light map to see where the light reaching your eye comes from, or the facet mesh to see the true facet edges.
When you have a stone you like, share it as an image or a link, or save its two-page report as a PDF.
Brightness & Tilt Analysis
The simulator shows you a stone; the analysis puts a number on it. For 21 cuts whose geometry has been checked against their GemCad cutting files, it measures how much of the available light a cut returns face-up, for the whole stone and for the table alone, under four standard dome models: Light Return, ISO, COS and SC2.
Two settings change the answer, and you can move both. Head shadow is the part of the light overhead that your own head blocks. Tilt tips the stone under a fixed dome, the way it moves on a hand, and a chart follows each model from −30° to +30°. Put two cuts side by side and every figure is measured under identical conditions. Every set-up has its own link, so you can send exactly what you are looking at.
It is a model of the geometry, not an assessment of any real stone, and we say what it leaves out.
How they fit together
Start in the simulator to see a stone and what changes it. When you want the number behind the picture, open the same cut in the Brightness & Tilt Analysis and read how much light it returns, and where it loses it. From the analysis, each cut links back to its page in the cut library and to the simulator.