Appears to me that it may have survived a fire. The color changes, the black soot-like stuff and the edge is cracked, like de-laminating. View attachment 594886 View attachment 594888 View attachment 594888 View attachment 594888
My first guess is that it was subjected to environmental damage. After 165 years or so, I guess anything is possible. Chris
Sentimental reasons for saving it, I guess. Surely not because it was worth something to collectors. Looks more like damage from a fire than from being buried. Lance.
Definitely looks like a fire coin due to the color and black scale, so I think you're right. Many types of environmental damage leave pitting as well discoloration and I don't see any here.
It is damaged; yet there are a large number of experienced numismatists/dealers/collectors who have seen enough coins to be able to tell what caused this type of damage. I'm not one of them; however, IMO only two things for sure, that coin was NOT in the ground and it is corroded.
While metal detecting in the cellar hole of a house that burned many years ago, I found one with similar characteristics, leading me to think that the op made a reasonable observation of fire damage.
I suspect the coin was stuck in a saltwater fish/reef tank, or was in salt water where red coralline algae grows. The red scaley color reminds me of it. My previous hobby was a saltwater fish and coral. I had a reef tank and this red/pink coral grew all over the place.
Here's an image I found. On flat surfaces as the side of a tank, it grows somewhat flat and can form scales much like what is on the face of liberty. When the object is removed from the reef environment, it will eventually flake off and loses some color, but it can stubbornly persist.