What could have caused these pits? Exposure to the elements? And I think I might have a possible die clash.. what do you guys think???
I don't know where you think you see a clash, but whenever I see "green", I immediately think of PVC contamination and/or environmental damage. Chris
Sorry, but your coin has a lot of corrosion which causes damage to the surfaces and that's what you're seeing. Anytime you see major corrosion or numerous scratches, nicks and dents, nearly anything that might resemble an error is due to the Post Mint Damage (PMD)
On the first one, I agree with environmental damage. Things will eat through copper over time. Pollution, acids, air, water, a host of chemicals. If that coin was laying in the ground before it found it's way to you, all kinds of things can react with it. On the 1926, the obverse looks cleaned, unless that's just the light/ flash reflection.
The 1926 is silver and shiny like a dime with copper showing through on the raised up details. Let me take a better picture