Toning And Discoloration On Coins

This is just a wild guess, I have no actual knowledge of this topic, but it seems to me that proof coins are more likely to show the effects of toning before a similarly stored uncirculated example.

I think it is because of one or both of these two reasons...

Either it appears to be faster because the otherwise perfect mirrored fields make the effects easier to see.

Or it is faster because the mirrored fields make it easier to spread, like flood waters over the plains versus the foothills.

This explanation I can totally agree with, in terms of the mirrored fields making it way easier to see imperfections, I bet that's 100% correct




This explanation, from a chemistry standpoint, is likely the reverse of what should happen. The rate of a chemical reaction has a lot of factors, but one of those is surface area, and a perfect surface with no bumps or grooves has a lower surface area. This means there is less area for reactions, like the oxidation that often causes toning.


As such, I would expect a BU coin to tone faster than a proof and just hide it better.

I agree with Noah!. oops I mean Jbuck..

Metal is metal and regardless of Proof or not, if in the same area. same results.