Digital Gemology | 3D models and cutting files for gemstones

Two kinds of file

One geometry, two ways to use it. Cutting files take a design to the faceting machine. 3D files take the same stone into CAD, rendering and jewelry manufacture. We build both from the same geometry, so the angles you cut are the angles you render.

One geometry gives both files: the angles in the tier table are the angles of the 3D model.

For cuttersGemCad

Cutting files

Everything a cutter needs to put the design on the machine. Every angle and index comes directly from the geometry.

.ascGemCad design file
.csvTier table: angles, indices and cutting order
DiagramPrintable faceting diagram

€9.99 per cut · Personal use Browse the cuts

For designersCADRender

3D files

Exact faceted models with flat facets and clean edges. They are ready for settings, renders and production.

STEPExact geometry for CAD
3DMRhino
STL, OBJMesh for printing and modeling
GLB, FBXRendering, animation and the web

€9.99 per model · Personal use Browse the models

Featured cuts

Eight of our 40 cuts. We sell each one as 3D files and as cutting files. Point at a stone to see its face-up light map, ray-traced from the same model. See every cut.

The collections

From the modern round brilliant back to the cuts of the seventeenth century, plus our own house cuts. If we rebuilt a cut from a historical source, the page of that cut names the source.

Free tools

Try a cut before you buy it. Every tool uses the same models that we sell, and every tool is free in your browser. All nine tools.

The 3D Gemstone Simulator: the 3D gemstone report on the left, a ray-traced round brilliant in the center, and the view and lighting controls on the right.

3D Gemstone Simulator Build a digital stone and read its 3D gemstone report as you go. You get any of our cuts in seven gemstones, the four Cs and ten kinds of light. Open the 3D Simulator

The simulator’s report is a simulation, not a grading report.

By gemstone

The correct angles depend on the stone. Each gemstone page ranks the top ten brilliants and jewelry cuts in that stone, by brilliance, fire and scintillation.

Measured, not described

A file is only as good as its geometry. How we check.

Constructed, not scanned

We build every stone from its angles and indices. It has flat facets and clean edges, and nothing is sculpted or guessed.

Checked file by file

Each 3D format has its own independent reader that opens it. We compare the cutting file with the model. If anything disagrees, the file doesn’t ship.

Measured by light

We ray-trace every cut in seven gemstones, so its brilliance, fire and scintillation are figures, not adjectives.

Before you buy

The short answers. The full answers are in the terms.

What is in a download?

The 3D files are STEP, 3DM, STL, OBJ, FBX and GLB, in millimeters at real size. The cutting files are the GemCad .asc design, a .csv tier table and a printable faceting diagram. Each is €9.99. A few cuts and the Platonic solids come as 3D files only. Each product page lists what it sells. Which programs open them.

When do I get the files?

Normally, immediately after payment. The download link and your license key are on the confirmation page and in the receipt email.

Can I sell what I make with them?

The standard license is for personal use: your own projects, stones you cut for yourself, and gifts. You need a commercial license to sell stones or jewelry, to do client work or to use the files in a business. Ask us, we are open to it.

Can I get a refund?

Yes. As a consumer, you can withdraw within 14 days of purchase and get a full refund, even after you download the files. A faulty file is repaired, replaced or refunded. Articles 10 and 11 of the terms.

Who takes the payment?

Lemon Squeezy runs the checkout as merchant of record. It takes the payment, charges any VAT or sales tax, and sends you the receipt and invoice.