Reference: File Format Matrix
Gem Diagram works with several file formats. This table summarizes what each format stores, what you can do with it, and when to use it.
Note
Importing, editing, and exporting any format requires the Pro plan. The Free plan previews the pre-loaded gems only — see Accounts, Plans & Billing.
| Format | Extension | Created By | Contains | Import | Export | Edit in Gem Diagram |
|---|---|---|---|---|---|---|
| Gem Diagram Native | .facet |
Gem Diagram Developer | Full design: all tiers, angles, distances, material, color, render settings, frosting | ✓ | ✓ | ✓ (yes) |
| GemCad | .gem |
GemCad (legacy software) | Tiers, angles, indices, optional RI | ✓ | (no, view only) | |
| Gem Cut Studio | .gcs |
Gem Cut Studio format | Tiers, angles, distances, indices, optional RI, sometimes frosting | ✓ | (no, view only) | |
| ASCII Gem Data | .asc |
Text editors, GemCad | Tiers, angles, indices, optional RI | ✓ | (no, view only) | |
| Cutting Report | .pdf |
Gem Diagram Export | Diagrams, tier table, proportions, stone stats (printable) | ✓ | (no, read-only) | |
| Screenshot | .png |
Gem Diagram Export | Current 3D viewport image | ✓ | (no, promotional only) | |
| Video | .mp4 |
Gem Diagram Export | 30-second rotating stone animation | ✓ | (no, promotional only) |
Key columns
Created By: Which software generates the file.
Contains: What data is stored in the file.
Import: Can Gem Diagram load this file? (✓ = yes, ✗ = no)
Export: Can Gem Diagram write this format? (✓ = yes, ✗ = no)
Edit in Gem Diagram: Can you open it in the Developer editor and modify it? (yes = full editing, no = reference/read-only)
Workflow summary
- Start: Create or import a design (
.facet,.gem,.gcs, or.asc). - Edit: Refine the design in the Developer (only
.facetcan be edited; others are imported read-only). - Export: Generate PDFs (cutting), or images/video (promotion).
- Archive: Save as
.facetfor future editing.
Material snapping
When you import .asc, .gem, or .gcs, if the file specifies a refractive index but not a material name, Gem Diagram snaps to the closest built-in material by RI. The rest of the geometry imports cleanly.
If the file specifies a material by name, Gem Diagram tries to match it exactly. If no match, the Material dropdown defaults to the design's current choice.
See Choosing a Material for the full list of 22 built-in materials and their indices.
Legacy formats
.gem and .asc are from GemCad, a retired Windows/Mac application from the 1980s–2000s. Many cutting designs exist in these formats. Gem Diagram can import them, but you can't edit them inside Gem Diagram — save them as .facet if you want to edit them later.
Switching from another tool? See Gem Diagram vs GemCAD or Gem Diagram vs Gem Cut Studio for detailed comparisons and import walkthroughs.
See Saving & Opening Designs for workflow details.