1906 IHC - How To Get Rid Of The Green On One Cent?

I would go with an acetone bath first and then some Verdi-Care on it.

Hopefully, DOCC will chime in. He has really good experience.
He metal detects as well & has done some amazing conservation work on all kinds of metal coins.
(He has some low key links in the signature part of his posts for those that are curious. I recommend giving the links a try. No, we're not related but I really admire his success.)

Well shucks PP55, thx.

CCMorgan, absolute and unequivocal NO to any acid. Vinegar & LJ are both acidic with pH levels of 3 & 2. Running thru the Polarity Ladder will do nothing for the corrosion but may certainly brighten the entire coin. Verdicare is what can address the corrosion - at best remove or reduce, at worst simply neutralize.

You may be able to improve the appearance but won't be able to clean up the green totally.

"Green" can be caused by several things. Each of those things needs a different kind of treatment.

"Green goo" comes from coins sitting in plasticized PVC coin albums. It's sticky, and tends to accumulate on the high points of a coin - the bits that were actually touching the plastic. Green goo is readily removed with acetone, though because the goo is acidic there may be underlying damage to the coin that the acetone reveals. This green stuff on your coin doesn't really look like green goo.

"Verdigris" is corrosion. It can be various shades of green, or even bluish-green, depending on exactly what kind of chemical environment caused the corrosion. Unless the green stuff is unusually thin, whatever treatment is applied will likely cause the coin to look "cleaned". Most chemicals that are strong enough to remove the corrosion will also strip away the patina and toning. Ammonia, for example, is great at removing the green stuff but will also make the coin turn an unnaturally bright orange. Corrosion usually needs either chemical cleaning such as acids, bases or chelating agents, or physical removal by scraping it off with diamond-dusted dental tools - and neither of those options are optimal and are also very easy to "do badly".

"Bronze disease" is a particularly nasty form of corrosion. It is typically powdery-pale-green in appearance, and it's nasty because it is "contagious" - it not only slowly spreads across a coin's surface, but can also readily jump from coin to coin if the coins are kept together loose in a container and flecks of the green stuff fall off and land on other coins. It's cause is not actually biological, but it sometimes behaves that way. It is thus important to treat bronze disease "at any cost", even if it means cleaning the coin to the point of it looking ugly. I've used ammonia to remove bronze disease - better an orange coin than a diseased one. Fortunately, the green stuff on your coin does not look like bronze disease, so should not need such urgent and drastic treatment.

Thank you one and all, always a learning experience for me and you all are great on shedding light on my lack of knowledge.