Goldbud ping.
Goldbud ping.
Electron shell.
platinum 2, 8, 18, 32, 17, 1
gold 2, 8, 18, 32, 18, 1
mercury 2, 8, 18, 32, 18, 2
There was an interesting experiment some time ago that involved taking a very thin sheet of some element and bombarding it to knock off a proton thus transmuting it into a different element. They expected a few atoms in the entire sheet, and were surprised that far more were transmuted than they expected.
In 1919, Ernest Rutherford transmuted nitrogen gas into oxygen by bombarding it with alpha particles, adding a proton, for example.
Other transmutation can remove a proton with a high energy photon (photodisintegration).
Thus you can add or delete protons from atoms of an element to change it into a different element.
While this was done in a lab, theoretically at least it might be turned into an industrial process. Not necessarily to turn mercury into gold, but to turn gold into platinum, which is far rarer and more useful.
In practice, molten gold would be machined into a thin sheet, then bombarded with high speed photons, then remelted to extract the platinum atoms from the gold. Then the gold would be reused.
The process would run continually, and while it would be very expensive, it might be competitive with mining and processing platinum from very low grade ore.