I have mentioned this before.. And I will state that this is just my opinion.. I have found these before.. It's unfortunately urine residue Now go wash up!
If others don't agree they will say that it is some kind of Environmental Damage. Probably a chemical spill of some sort.
Im new to coins collecting so ive been just digging everywhere for coins. Any coins that look funny or different im keeping it. I dont if thats a good idea or not. But heres two more coins that i thought is pretty cool. Penny is thick planchet and nickel had different toning and it was from uncirculated roll.
Cool The thick Cent could be struck on a thicker than normal planchet or one side could be wider due to a high pressure strike that will create a finned rim. And your second picture confirms the raised rim due to High Pressure Strike.
I would tend to go more with a "heat-induced toning" verdict on the coin in the OP rather than "urine residue", but of course I dunno for sure (and don't really want to scientifically test the difference, LOL)
Probably urinated on by a Confederate soldier reenactor/living historian. Many of them despise Lincoln. At Gettysburg, some of the souvenir dealers during special events even refuse to take pennies or $5 bills because they can't stand to see his face.
I was (very briefly) a CW reenactor in my college days, in the 12th Georgia Infantry, Company I, and never saw any such silliness, though I do know reenactors can be a cantankerous and occasionally insane lot.
For comparison, here are pics of a 2005 Dime found in a cup holder of a Tahoe. It was in petrified Coke or Pepsi, and has pink, orange, and purple hues with etching after I washed off the pop. I wasn't able to capture the iridescence since I was too stubborn to get my camera and just free handed it with my phone.
