"Even with my very limited knowledge of mold production and injection molding, my limited experience tells me you're barking up the wrong tree when it comes to the software, process and type of equipment you think can be used to create those sort of parts."

If you don't have any experience with what is being used in the Jewelry industry, then you would not understand that there is a big difference in what is an acceptable 3d file format.

I suspect this comes down to the fact that they are using much smaller CNC machines, and are not pushing around as much mass of the machine to do the milling.