Given it looks dug, it has probably been in acidic soil which has reacted with the metal over time and reduced the weight. You will get metal loss across all surfaces assuming the coin was fully in contact with wet soil which ought to mean the coin is roughly 20-25% thinner. i.e about 1.3-1.4 mm thick and a corresponding reduction in the diameter. That's assuming equal reduction everywhere and not allowing for preferential ingress of reactant into the metal where there will be flaws in the crystalline structure at the microscopic level due to metal flow on striking.
Thank you for all that information greatly appreciated Another thing I've never seen such a gold looking penny it's so gold looking
Also I can see polish marks throughout the whole coin obverse and reverse from the mint like you know that the die scratches the Polish marks why would that be if there was acid on it then those would be gone too wouldn't they
If you put a coin in acid (think something like coca-cola) then it changes colour. That will depend on how it reacted. Cleaned bronze is often much lighter colour than the original surface. That's corrosion visible. Polish marks are very fine parallel lines and would be much lower relief than the pits seen.
The Polish marks are going over over the pits I mean they're so they're so perfect I don't know bro I can't look at this thing no more killing more thank you