Does the annealing process effect toning?

I'm sure you know that it's not sheets of silver that are placed in the annealing furnace, but individual planchets. And no, it is not an assumption, it is a fact. They do go through the same annealing process. The planchets for Morgans and for Peace dollars were identical - same diameter, same thickness, same metal alloy.

The OP's original question was if the different heat source - wood vs gas - was a possible reason for the lack of Peace dollar rainbow toning. Now logically a person might think so. But that reasoning would also mean that all other coins annealed with gas heat would not have rainbow toning either. But they do have rainbow toning. So logic dictates that gas heat is not the reason. It had to be something that was specific to the Peace dollars. And the only there is that was specific to the Peace dollars and to no other coins was the die preparation that resulted in them having a unique type of luster. No other coin minted , before, during, or after the time Peace dollars were struck had the same type of luster that Peace dollars do. And since Peace dollars are the one and only coin there is (other than gold) that is not commonly found with rainbow toning then logic dictates that their unique type of luster must be the reason for their lack of it.

Now you can say what if till the end of time if you wish. But what I have related above is solid reasoning.

 

The Walkers and SLQs are less scarce than some other coins, quite true. But nowhere near as scarce as rainbow toned Peace dollars. There is no coin, (US anyway) from any age that is as scarce as rainbow toned - I won't even say rainbow toned, I'll say colorfully toned - Peace dollars. None !

edit - as for my theory. I'm more than willing to listen to any other possible explanation. But so far, mine is the only one that stands up.

 

Yes that has been said. But it's just like the annealing process. If the planchet wash was the reason then why is it that all of the other silver coins of the time were not affected in the same way ?

While the mint was known, and still is known, to change things like the wash solution, they used the same wash solution on all planchets of the same metalic content. In other words all silver planchets were of the same identical alloy so they washed all the various denomination planchets in the same wash solution. And yet they all toned quite colorfully - but yet the Peace dollar did not.

Thus the only viable reason is still the unique surface finish that the Peace dollar has.