Here are the best photos we could manage. There is no silver color showing on any raised areas where wear would be expected. Any thoughts?
There is no silver to show. Nickels (except for 1942-1945 War Nickels) are copper (75%) and nickel (25%). Your coin appears to be discolored. It may have been dropped and spent a period of time on or in the ground. I have found many nickels with my metal detector that look like your coin.
Sintered I have a few similar nickels. I believe the difference came from the prepping of the planchet. Try Binging/Yahooing/Googling Sintered. I have a wad of Keelboat nickels, pulled from the mint shipping with similar "Special" appearance.
The dealer in my town has a PCGS graded 1943 copper war nickel , it really is just one of a kind ! Until someone finds another. Someone had brought it in to them years ago. I couldn't believe the coin existed either until I saw it myself.