I have seen several brand names of "spot removers" cussed and discussed in the CT forums. Advice requested. I have an uncirculated 1951 Canadian half (80% silver) with a 2mm spot on the obverse. Under 10x, the spot is black gunk, with greenish verdigris-like stain all around it. Yes, I know, a green stain on a silver coin seems counter-intuitive, but it's there. Please discuss some of the trade chemicals for removing it, by brand name; considering the relatively small value of the coin, and the modest increase in value from removing the spot, no "fix" should cost over $5.
Leave it be?! A $20 coin (at most) that looks ugly as sin? Anyhow, you aren't answering the question I asked -- brand names, personal results? There's probably half a dozen kinds of little bottles of "stuff" out there, and I don't know anything about any of them. If I wanted to leave it alone, I wouldn't have posted the topic.
You might try a product called EZest Coin Cleaner. I have used it on some junk (and I do mean junk) silver and it does a good job of removing grime. You'll get the usual sermons on cleaning coins, but if you really want to clean it, go for it.
The REASON I don't know anything about what's "out there" is because I don't clean coins. This is a harmless, exceptional case for a piece of very nominal value; if I don't like the results, I can sell it for bullion. Try to keep some perspective here.
Yeah, I know what you mean -- I've got a jar of EZest, but I still haven't opened it. I have no idea what it would do with the copper salts you describe. If it seems like "gunk", I'd probably be inclined to try acetone first -- but, again, I have nearly zero experience, so I'd wait for more advice.
Have you tried white vinegar on it? It's not going to remove the spot but it will darken the green and improve the appearance of the spot. I use a toothpick to apply the vinegar when it's a small spot like that. Just keep applying the vinegar and don't let it evaporate until you get the spot where you want it, then take the coin to the sink and rinse it under water. If you're a purist, rinse in distilled water. If you let the vinegar evaporate before the rinse you may leave an unsightly ring around the spot.
Technically, you did not ask any question, however, you did ask for a discussion. I just went beyond what you wanted to hear. It appears you only want someone to tell you what you want to hear before you do it. As you said, it is a $20 coin, don't waste our time. Do what you want.
