OffTheDop
✦ Bench & Geometry Notes

Light, Geometry, and Oddball Experiments in Gemstone Design

Stories and visual experiments exploring what happens when software tools meet a real 96-index faceting wheel and a 10× loupe.

A quick note: I’m not a trained gemologist. No GIA diploma, no mineralogy degree, and no traditional bench apprenticeship. Just a software engineer who fell down the rabbit hole of faceting machines, geometry, and how light bounces around inside crystals.

Seven-sided Padparadscha-toned Spinel heptagon Gossamer Luster 321 throwing warm 7-petal caustics across a dark studio table
✦ New Feature • 17 min read

FROM SLIDE RULES TO 3D RAYS: FIVE VINTAGE FACETING RULES AND WHAT LIGHT ACTUALLY DOES

Beginner handbooks and jewelry-counter folklore still repeat five pre-computer rules of thumb that gemologists and custom faceters retired decades ago once 3D ray tracing arrived. Here is why those early shortcuts existed, how ProFacet and OffTheDop define A True Window, and what 3D light, skin oil, binocular vision, and dispersion really do.

Physics & Optics Craft & Practice
Read Article & View BDPT Comparisons → Explore Odd-Symmetry Cuts →
Origami Kitsune Fox carved into a Royal Blue Sapphire crown
✦ Featured Story • 19 min read

FOLDING PAPER IN CRYSTAL: TEACHING A 96-INDEX GEMSTONE TO CARVE ORIGAMI

What happens when you try to carve a folded-paper fox or crane out of real crystal facets on a 96-index machine, without lasers, stencils, or uncuttable decimal depths? Here is the story behind our self-erasing temporary help-cuts, all 108 crown blueprints, and why every single design is free ($0).

Computation Craft & Practice
Read Story & View 108 Animal SVGs → 🦢 Browse 108 Free ($0) Cuts →