 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 was 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 was envolved. Image - JD White, camera - Nikon Coolpix 950 Digital. |
|
|