GemDiagram Docs

Reference: File Format Matrix

GemDiagram 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 a Starter plan or higher. The Free plan previews the pre-loaded gems only — see Accounts, Plans & Billing.

Format Extension Created By Contains Import Export Edit in GemDiagram
GemDiagram Native .facet GemDiagram 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 GemDiagram Export Diagrams, tier table, proportions, stone stats (printable) ✓ (no, read-only)
Screenshot .png GemDiagram Export Current 3D viewport image ✓ (no, promotional only)
Video .mp4 GemDiagram 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 GemDiagram load this file? (✓ = yes, ✗ = no)

Export: Can GemDiagram write this format? (✓ = yes, ✗ = no)

Edit in GemDiagram: 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 .facet can be edited; others are imported read-only).
  • Export: Generate PDFs (cutting), or images/video (promotion).
  • Archive: Save as .facet for future editing.

Material snapping

When you import .asc, .gem, or .gcs, if the file specifies a refractive index but not a material name, GemDiagram snaps to the closest built-in material by RI. The rest of the geometry imports cleanly.

If the file specifies a material by name, GemDiagram 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. GemDiagram can import them, but you can't edit them inside GemDiagram — save them as .facet if you want to edit them later.

Switching from another tool? See GemDiagram vs GemCAD or GemDiagram vs Gem Cut Studio for detailed comparisons and import walkthroughs.

See Saving & Opening Designs for workflow details.