How do I clean an 1886 Nickle I found buried while metal detecting? It IS Nickle & first minting of its kind.?

I found this in my yard, about 8 inches deep in a sandy type soil. I can see the 1886 date, stars around the coins edge, and part of a Roman numeral V on the reverse. The trouble is that it is VERY dirty and I do not want to harm anything on this coin.

Pure nickel will clean in ammonia or vinegar, and responds to Tarnex like it should. Extremely light Brasso also.

Copper-nickel, on the other hand, will quickly develop pitted surfaces in all four solutions. You can dunk copper-nickel coins when you have to because of unsightly spots, etc., but get them in and out fast: not more than a few minutes for ammonia and vinegar and not more than a couple of seconds for thiosulfates.

Metal Detecting Finds