Grease or Man Made?

[BuffaloHunter]

Hello all, I know I post a lot regarding "errors" and come out looking stupid. But I thought this nickel looked interesting. It's a 1971 D Nickel, could be a grease or it's just been acid applied. The date is smoothed out but still readable, there is a bit of a black coating that could be some type of oil or gunk but looks natural to me. Any opinions would be appreciated! ( Any book recommendations for errors or cherry picking?)

-Buff

 

Amazon Forum Fav 👍

Minelab PRO-FIND 35 Waterproof Pinpointer Metal Detector for Experts with Tone ID & Adjustable Sensitivity - Grab it through Amazon!

[BuffaloHunter]

Here are the photos..

 

[enamel7]

Looks like normal circulation wear to me. Don't confuse grease on the coin with a strike through grease error. They aren't the same. Cherry pickers guide is good for varieties.