Came across this one while looking thru some ole what's and jeffersons, thought it was a penny at first but too large. We think that it is some type of environmental damage but just have no idea what caused it. Any help is appreciated. 8
That would be exposure to the environment. Nickel contains 75% Copper. It tones over time. Here are my metal detected examples.. Clad also has 75% Copper
Remember this.. If it were struck on a Cent Planchet it would be the same width, thickness and weight of a Cent Planchet. Here is an example from my collection -
When copper-nickel coins corrode, they turn black or brown. That is true for nickels and clad dimes, quarters, half dollars and dollars.