I recently acquired this 1794 Large Cent which, yes, has been cleaned, compromised and has probably been through some historic trials and tribulations, but it's still my only 18th century US coin, so I'd like to treat it well. So... ...in hand I don't see anything suspicious, but upon magnification with a loupe I see a few spots on the reverse which have little green spinach-colored flakes in them. They are quite small and require decent magnification to see. In case it doesn't show up well in the photos taken with a USB scope, the green spot is at the bottom of the "O" and a small line exists at the bottom of the "E" in cent: In this one a greenish blob appears at the bottom of the "A." So, is this verdigris? Is it possible to tell from the photos? If it is, should I use something like Verdi-care on it? Or is it so slight as to not be a problem? Or will it become a problem if I do nothing? I'm a verdigris newbie and I'm excessively paranoid to do anything to this coin without guidance from someone more experienced. I have heard that one should pretty much use nothing except for Verdi-care on such growths. Any thoughts or advice would be greatly appreciated! Thank you!
You could try Verida-Care, but on verdigris that appears that old and hardened I doubt it would do much good. But it might. You could also leave the coin alone. Given how pitted it already is by past corrosion those little bits of verdigris aren't going to hurt it any. Especially if you store it correctly. I say that because verdigris is inactive, it just sits dormant, when there is no moisture present.
Nice Photography.... what exactly is a USB Scope? Also... I love the coin, I can't quite tell if has the Head of '94 or '95. Either way, it is probably F condition, which makes it great! I would personally leave it alone with the corrosion present, and agree with the above comments. My 1794 is AG, I think, LOL, and still looking for a 1793...
Fantastic! Thank you for the responses! All of my numismatic reading over the years has emphasized leaving a coin alone unless some drastic circumstance arises, so I will follow that and all of your advice. I am very happy with that answer and I'll be extra vigilant to keep the coin away from moisture. As for a "USB Scope," @DallasCoinsNThings, I was too lazy (or in too much of a hurry) to type out the entire description. I use a plugable USB 2.0 Digital Microscope (which plugs in via a USB port) for taking extreme close-ups. For the surprisingly low price, it does an excellent job. Someone on this very forum recommended it and I'm still grateful.
Those look like old deposits. Check out some of the ancient coin threads to see more. Keep your eyes out for bright green, powdery spots. They should flake off easily. On your coin, those adhesions or deposits look stable. I am not an expert!
Dead on Conder101- doubled lowest lock, defect in left obverse field. An interesting obverse (# 11), as Sheldon numbered 3 different obverses for the same die due to mint touch-ups and lapping keeping this one in service- actually used for S-30, 31, 38, 39 and 40!
Definitely NOT verdigris. It's corrosion. Minor, and the con is otherwise porous, so I wouldn't do anything about it. VerdiCare does not get rid of verdigris, so don't waste your time with it. If you brush it with a little oil - the current iteration on sale is called Classic Coin Conditioner - you'll keep it from getting any worse. Others have given the variety, and I agree. One of the few varieties than I can identify at a glance.
Given the implications of your comment, I'm posting this merely as a point of clarification. Verdigris does not cause corrosion, verdigris is nothing more than the result of corrosion, it is the material produced by the corrosion of copper. In other words, verdigris used to actually be copper, but because the copper corroded, some of that copper was turned into verdigris by that corrosion. It's just like it is with most other chemical reactions, when you mix two or more chemicals together, they cease to be what they used to be and are turned into something else. Verdigris and copper are just like rust and steel, one used to be the other in both cases.
