[didericis]

I have a vague memory of someone or some article saying there’s a way to get from lead to gold if you really wanted to with some combination of available nuclear tech, but it’d be completely absurd/ludicrously expensive (I think the context was somebody humoring what would be needed for atomic level assembly/star trek replicator stuff). I assume the same would apply to iron.

[andrewflnr]

Yeah, but even worse. You need to add a lot of nucleons to iron just to get to (impure, radioactive) lead, and then from there to gold.

[cowpig]

Iron (26) -> Lead (82) -> Gold (79)

How does that work?

[andrewflnr]

Ha, woops. I was just assuming Gold had higher atomic number. But I don't know, maybe a convenient positron emission decay path.

[Schroedingersat]

You smash a proton into it and knock a light atom nucleus off. Works every time about 2% of the time.

For the stuff that doesn't end up as gold you can just keep hitting it with neutrons until it's heavy enough to try again.