U could try giving it a soak in acetone maybe to loosen up the stuff on the surface ..
But I agree with Amida17- to me looks to be an average
Lincoln Penny ..
And just a lil bit of info - when posting photos , try to get it as close and clear as possible (i know its tough took me awhile to get the hang of taking photos of coins).
But also take pics of the obverse / reverse then the area you maybe seeing something out of the norm ..
.. I'm sure you may know already but I just wanted to give a friendly reminder in case you happen to find something else again and it would make helping you out 10 times easier :-) ..
Best of luck on your searching .!!
Look forward to seeing what you find -
Phil \m/