Enable "Gemgen" (or "Gemgen Lite") in the add-ons list.
Requirements
Blender 4.0 or later is required. The add-on has been developed and tested on Blender 5.0. No external Python packages are needed.
Editions
Gemgen (Full): all 10 cut types plus a sample scene.
Gemgen Lite: Round cut only — the affordable entry edition for trying the tool. Lite owners can upgrade to Full by paying only the price difference on Superhive.