Hanging 3 And Some Sort Of Added Material On The 1

First off acetone is not considered cleaning your coin. It will not cause any harm and only remove what you don't want on your coins. Just make sure you don't rub the coins. A soak and a rinse in fresh acetone or distilled water is is a good way to remove debris from your coins. I recommend an acetone bath and then see if what ever is between the 1 and 5 disappears. It could be damaged permanently though by the mark there.

Is the mark raise or incuse on the coin? It looks to smooth to be a die chip. Also it's best practice to posts both sides of the coin for best responses. When I first saw the cent you posted my mind went to is it NSF or SF.

To me, acetone IS considered as cleaning your coin and, as bosox says, it CAN affect the color and luster of the coin. Acetone should be used only after trying any other non-invasive method with no luck. It is primarily used to remove the green grunge or green oily stuff that shows up on coins. Acetone can be harmful to coins that have had OTHER solvents that had been applied to the coin, many times without your knowledge. You can use acetone after other methods have failed, especially the green verdigris that has hardened and probably coroded the surface.

Good to know. I have not cleaned many of my coins, only a few cent coins to test out the efficiency against the green stuff on cents. The odd time it made the green turn almost a blue colour and spread, further, after which I soaked for 24+ hours and it usually got rid of the green/blue but just revealed the pitting underneath. If I do clean more of my cents I'll remember to try distilled water first. I read for nickel coins distilled water is better then acetone, but don't study much about cleaning coins since I usually don't clean them. I guess to each there own. I'm sure there is cleaning methods people use that are effective safe and others don't know about. I have heard of olive oil being used to remove surface gunk etc as well though don't know if it's safe.

Bill, I have done that for the same reason as Haxby. The heat tends to wash out the surface of the coin and leave it a very blah, dull brown. Works like a champ to remove the gunk. You will not get one through a TPG after that.

Well,
Maybe practice on some coins that wouldn't change value one way or another.
Maybe you can find a way that works for you.
I personally haven't found a good way to clean copper or bronze and retain color and luster.

This also happens as a photochemical reaction between mint state copper and/or bronze and the acetone with sunlight or bright light. It leaves a "gasoline on water" rainbow effect on the coins.

http://www.sciencedirect.com/scienc...468601003590

From what I have gathered from this thread, as long as the copped/bronze coin soaking in acetone is in a moisture free environment with no to little light should result in no issue to the coin being soaked. This does not account for foreign chemicals that may be on the coin. So a distilled water rinse followed by a proper drying and an acetone soak in a sealed container away from UV rays should be completely safe and not harm the coin. Great cleaning info.

Let's stop the cleaning debate and focus in the OPs coin and there question. I had no intent to hijack this post and turn it into a cleaning coin topic.

Still waiting on obverse pics, I have no comment on the issue between the 1 and 5 based on the photos. If it comes if with a "proper cleaning" then it's foreign substance in the coin, if not then a possible lam or maybe something else. Definitely looks to smooth to be a die chip IMO.