 1940 Jefferson Nickel. Black toning may be due to circulation combined with storage in an extreme environment and possibly high cobalt content in the nickel, but I suspect sulfur is envolved. Image - JD White, camera - Nikon Coolpix 950 Digital. |
1940 Jefferson Nickel. Black toning may be due to circulation combined with storage in an extreme environment and possibly high cobalt content in the nickel, but I suspect sulfur is envolved. Image - JD White, camera - Nikon Coolpix 950 Digital. |
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