Has anyone ever heard of a jewelry-scale random orbit polisher of
Yes, there is such a thing. It's generally used at monument works(gravestones) and, I would think, would be useful only for very largepieces of stone.
I've mentioned this company once before; Micro-Mark. Although theysell tools for the modeling field, much of what they have applies tojewelry. They have a couple small sanding tools that work as anorbital sander. I'm unsure if they will have the papers or gritsneeded for jewelry or stones, but check them out. www.micro-mark.com