Thanks for the input. Your conclusion is certainly based in logic. One piece of missing information may, however, undermine the conclusion. We don't don't know if the thickness of the coin is also equal, as is the diameter.
Would it be possible to tell the difference visually by, say, color? This coin is a shiny silver color with what appears to be the slightest beginning hint of an even champagne toning. Would the copper-nickel produce more of a copper color? The fields are not mirror-like as one might expect from a proof.
I am trying to avoid removing the coin from its holder in order to determine, with certainty, the composition of the metal in this coin.
Would it be possible to tell the difference visually by, say, color? This coin is a shiny silver color with what appears to be the slightest beginning hint of an even champagne toning. Would the copper-nickel produce more of a copper color? The fields are not mirror-like as one might expect from a proof.
I am trying to avoid removing the coin from its holder in order to determine, with certainty, the composition of the metal in this coin.



















