I found this 1916 Wheat penny
while coin jar hunting and was wondering about the toning on this coin. The obverse has brown toning and the reverse has red toning. Could this 2 toning have occurred from sitting in a glass jug with a lot of other pennies? Is this 2 sided toning rare?
Also wanted to ask weather this is a proof penny? I read that square rims are an indication of a proof pennies. How can you tell for sure when searching old pennies?
I have attached 2 photo's to show the obverse and reverse at the same time after being photographed in a mirror in a coin flip.(which was not that easy to do!)