- First, get some mercury. The kind we want is Hg-196, a naturally occurring isotope with 80 protons and 116 neutrons in its nucleus. The 80 protons are what make it mercury. Gold, meanwhile, has 79 protons — you see where I’m going with this. Finding sufficient Hg-196 could take some doing, though, as only 0.15 percent of mercury is in this form.
- Slam a slow neutron into it. Initially I was unsure how one went about this. The journals said the desired type of neutron had an energy level in the thermal range. This to me suggested you could just heat up a can of neutrons on the stove and drop in some mercury. However, I suspected subtleties were being overlooked. I set this matter aside for further study.
- The slow neutron is captured by the nucleus of the Hg-196. This turns it into Hg-197, with 80 protons and 117 neutrons. Hg-197 is unstable. In 64.14 hours, give or take, electron capture occurs. This means the Hg-197 grabs an electron from a low-hanging shell, combines it with a proton to make a neutron, and kicks out a neutrino.
- Discard the neutrino. We have no need of it.
- The Hg-197 has now turned into something with 79 protons and 118 neutrons. Do you know what this? I’ll tell you. It’s Au-197, the only stable isotope of gold.
- Repeat five zillion times, until you have enough gold to make an ingot. Success! However, if you didn’t do so earlier, you must now separate the stable gold deriving from Hg-196 from the unwanted crud deriving from the rest of the mercury, which I remind you constitutes 99.85 percent of what’s out there and a good chunk of which I’ll bet is now radioactive. So it could be a long afternoon.
→ Straight Dope on how to transmute base substances into gold