GemDiagram Docs

Quick Start: Make Your First Gem in 5 Minutes

You'll design a round brilliant cut, customize it, and save it. No experience needed.

1. Start a new design

Open GemDiagram and click New Design. A dialog shows two paths: Guided (step-by-step wizard) or Manual (blank tier editor). Pick Guided for your first gem — it walks you through it.

2. Name it

The wizard asks for a name. Type "My Round Brilliant" and click Next.

3. Pick a shape

The shape screen shows Round is already picked (the default). Click Next.

4. Check the symmetry

Symmetry is set to 4-fold, mirror (the right choice for Round). Click Next to enter the design step.

5. Adjust the pavilion

You're now in the Design step, viewing the Pavilion tiers (the back facets, shown below the stone's widest edge). Two tiers are pre-seeded:

  • P1 (Pavilion mains) — 8 big facets that bounce light back up
  • P2 (Pavilion breaks) — 16 smaller facets between them

The defaults are fine. Click Continue to Crown to move on.

6. Add breaks to the crown

You're now viewing the Crown tiers (the front facets, above the widest edge). Three tiers are pre-seeded, but C2 (Crown breaks) is empty — the wizard is waiting for you to add facets. Click the index gear at position 0, then at position 12 (two clicks, because of the 4-fold mirror symmetry) to add an 8-facet star pattern. Click Continue to Girdle.

7. Review the girdle

The Girdle (the stone's edge) is already set — it's a ring of facets running all the way around. Click Finish to see the full 3D stone in the editor.

8. Customize and save

In the editor, you can:

  • Change the material: Open the Inspect panel (right side) and pick a different gem from the Material dropdown.
  • Adjust tiers: The Build panel (left side) lists every tier. Click a tier name to highlight it in 3D; drag the angle and distance sliders to reshape it.
  • Save: Click the Save button (top bar) to download your .facet file.

That's it. You've designed a gemstone, previewed it in 3D, and exported it ready for cutting or further refinement.

Next steps