As of January 2023, GemCad and GemRay can be downloaded and used with the free registration keys.

http://www.gemcad.com/ ***"so long as this (his, Roger Strickland) site is active"***

http://www.gemcad.com/purchase.html

Could the file formats be translated to MoI 3DM?
I'll have a look when time becomes available...

- Brian

https://famousdiamonds.tripod.com/gemcadfiles.html

Then again, maybe the gem files and programs are obsolete or ???
https://www.gemsociety.org/article/designs-designing-gemcad/

Seems all format files from GemCad are not reloaded by any progs! :(
too old versions!
Not evident prog! :)

Edit
I have found a workaround!
Import the DXF inside the free Pcon Planner! https://pcon-planner.com

Export as OBJ & double faces! (curiously exported as DXF is not reloaded by Moi ! )
_import OBJ... (by Max Smirnov)

Hi Pilou,

re:
> (curiously exported as DXF is not reloaded by Moi ! )

DXF files can contain a lot of different kinds of data. MoI's DXF importer is only focused on processing 2D drafting data like lines, circles, arcs.

It is likely that your DXF file contains polygon mesh data in it (which MoI does not process) and not drafting data.

- Michael

thx for the infos!