Is there anyone that can tell me about the black residue on this Penny? Will it damage the coin, what can I do about it?
I think your coin has serious corrosion issues and with that has lost most if not all of its numismatic value. Here is a site that may help you. http://www.metaldetectingworld.com/cleaning_preservation_coin.shtml
Try using a pointed toothpick. A trick of the trade by our local P.HD Numismatist, it sometimes works on blackened corrosion. Couldn't hurt, the damage is already there. It will not damage the coin unless you push too hard. Good luck.
Thanks to all for the information. Fortunately, it’s the only coin with this. Sadly, it might’ve been a good coin at some point. It was like this when I inherited it.
A sharp ROSE thorn will remove dirt and it is soft enough not to damage the copper. Soak in olive oil a few days first to loosen the crud a little. Try it, it can't hurt the value of the coin in the picture.
I might add that you could do it while submerged in acetone. Also, after that, treat it with Verdicare to preserve it.
I prefer bamboo sticks used for grilling on BBQ. The 99 cents stores usually sell them. Some are large , but some also small , pointed on both ends. Bamboo is almost entirely tubules and the tip in solutions ( water, chemicals , etc.) and it draws the solution up into the pick. Roses don't grow well here so the 99cent stores are always here . Jim
The 1860 Indian cent is made with a copper-nickel alloy that is different from the later pieces which were made on bronze planchets. When that alloy corrodes, it most often turns black or dark brown. The natural color for these coins when they were made is white, like the modern 5 cent piece. I doubt that much of the stuff, especially on the obverse, will lift off of the coin. Here is a mint state example. Here is bronze Indian Cent. The alloy was changed in 1864.