Hi I came across this and instead of comparing this to ebay coins I came to the pros to let me know if this something special. It does not appear to be dirt color but a weird black.
That's unfortunately.. Environmental toning Nickel is composed of Cupro-Nickel. The copper mixed with the nickel will tone dark if exposed to the elements. People try to sell those on eBay as Improperly Annealed planchets. Don't even bother looking at ebay or etsy. Always come to us first.
Here are many of my environmental exposure toning examples I have found metal detecting. On Clad and Nickels
Wow a couple of them look like mine I am glad I asked I think I will keep it for future reference thanks so much
There are something call "black beauties" on the 1959 and some 1958 nickels. An improperly annealed planchet (cooked too long), and they can appear darker. Of course what Paddy is saying is correct about env. damage. When you dig up coins, the combination of air, water, soil, chemicals, pollutants will react with the metals in your coins and they get "rusty". The coins can still be spent, and this is what you get. 1964 they over produced nickels (and dimes and quarters) which is why you still see a ton of 1964 nickels today. And when you find a silver coin it is often a 1964.