Interesting idea, but:
1) 100Mo is only 9.6% of natural isotopic content of Mo. So, add a step and make it 200$ per kg. That's not the issue, the issue is time it takes to do
isotope separation. I wasn't able to find the data for Mo, and data for U is most probably classified, but that isn't a fast process.
2) 100Mo is transmuted into 101Ru, not the natural isotopic content. We need a further reaction to transform it into 102Ru, which is probably done via
101Ru(p,d)102Ru reaction (it was the only one I was able to find). This takes time, produces a lot of radiation (which would cause activation of all materials around us and probably kill our family), and most likely has separate reactions going on (i.e. the output is below 100% 102 Ru, with a lot of other nuclear products which has to be separated from the output).
3) 103Ru transmutes to 103Rh with a lifetime of 35 days. Assuming that we get a 5 time rate increase for a natural decay, where we don't actively affect the material at all (arguable), it's still 35 days of constantly running TTC to make 103 Rh non-radioctive (it is generally considered safe after 5 to 10 half-lifes to handle radioactive material).
4) The price of Rh is
very non-stable. It is in fact the most unstable precious metal on Earth.
5) The amount of attention this will bring to us is much higher than diamond production. A very smart high schooler could, in principle, make a CVD installation in their parents' garage and work out a revolutionary production method. But elemental transmutation and isotopically pure rare metals is definitely nuclear stuff. Assuming that
radiation detectors around Chicago won't pick it up, resellers will have a lot more questions for us.
Iridium to platinum is possible, but not very profitable. Unless we build a radiation-resistant bunker where we will store the material as it decays, we could only use 193ir. It has
isotopic abundance of 62.7% sharply cutting into our profit margins.
These are interesting ideas, and nuclear-forged Rhodium would + synthetic gems would be rad materials for jewelry crafting (very small market, but very high price; probably present it to someone like Mab or someone else to demonstrate our supreme mastery of craftsmanship), but they remain much less feasible than gem making or jewelry making using normal materials.
