I bought a bunch of coins at a coin shop yesterday, including a lot from India. One of the 1 annas is not at all the color it should be. Krause says this coin is nickel-brass, but it is very chocolate brown, like the older quarter anna coins (bronze). Along the edge of the reverse side there is a little of what looks like the proper color for these, but it's faint so hard to say for sure. The edge itself is the same chocolate color. What do you think this is? It doesn't appear to be damaged like if a chemical was used on it, and I wouldn't think this color would be any natural part of nickel-brass (though what do I know?) I'm putting it side by side with another coin of the same date to show the difference.
I wonder if it was baked or something. I'm not sure how dark nickel-brass would get from oxidation, but most copper alloys would get darker and redder if you heat them. The fact that some of the coin still has the original color makes me lean against it being an error coin minted of the wrong metal.
That's what I was thinking too, about the color on the edge. Just seems strange though. Otherwise the coin is in good condition.
The color looks pretty even on both sides. If I were to try to replicate it by baking a coin in an oven, for example, I would expect the side in contact with a surface to be lighter than the side exposed to air. I would probably also expect some banding or irregularity to the surface color. I'm thinking maybe left accidentally inside a container in a hot environment or something. Mysterious.
