Indian Head Cent 1862 Cn Discoloration

Heavy environmental damage. Nothing you can do except get a better one

Tried to get that rusty discolored environmental stain off this 1862 CN Indian Head cent. I bought this as a problem coin along with 2 others a 1860 and 1874 for a total of $10 so about $3.33 each. No big loss if I destroyed it. Tried a soak in two tbs white vinegar, one tbs peroxide, 1 tspn soy sauce. This solution works good on no date worth nothing buffalos to bring back the date. Thought it might work on the Indian Head that is 88% copper and only 12% nickel with probably iron environmental damage. I think it did a pretty good job although it did dull the copper some and I guess because of the 12% nickel part of it. Has VF TO XF detail now and no longer ugly rusty stained color. First two pictures are with pluggable usb microscope which doesn't do a very good job with capturing true color. Last photo is with cell phone.