Not always but if a coin looks brand new like it just came out of the mint and you notice it has wear on it from circulation, there is a good chance it has been dipped to make it appear new. Some newer coins have been dipped in things like Acetone and it then is difficult to tell since if they are new they will still look new after dipping. However, some dipping solutions have a dentency to discolor a coin. For example I recently purchased a 1914D Lincoln Cent in what COULD have been MS60 but it was obviously dipped since it has a blue tint and shines just a little to much for a coin that old.
CARL, Do you see that blue tint at times on silver coins to, or does it show more on the copper coins?
If the coin is MS and shows no wear, and it has been dipped properly - you'd never be able to tell at all except by just plain reasoning. By that I mean that a coin of any age should have at least some sign of toning. But if the MS coin was over-dipped, then it will appear dull and lifeless and have little or no luster, it will appear a flat grey color. A circulated coin may have little luster due to wear. But if it is worn that much then there should be some signs in the protected areas and small tiny recesses of dirt or grime. At the very least those recesses should be darker due to toning. But if the coin was dipped, then it will appear to be clean and of a very even color over the entire surface of the coin, with maybe only a small spot or two of dirt or grime left in the recesses. And the amount of wear on the coin can be a give-away as well. For example, if the coin has XF details or better but there is no luster to be found and there is no dirt, no grime, no toning even in the tiniest recess - then you can bet the coin was dipped.
Ruben, would it be possible for you to get a pic and show us what you mean ? I've always wondered about that, but never realy knew if it was true. But then I've never tried to look at one thru a microscope either. It would be pretty neat if it was easy enough to do because there are a whole lot of collectors out there that just refuse to believe their coins have ever been dipped.
Of course what is missing from this subject is exactly what the coin is dipped in. Proper dipping also depends on what is used for a dipping solution and how it is dried afterwards. One thing I have done over the years lately is try dipping, toning, untoning, etc. with all types of coins. I've purposely bought cleaned, toned, dipped coins for experimental purposes. What so many of us forget though is the extensive differences in dipping solutions. Even the containers used can create differences. Most people think glass is a safe medium for containing solutions. Not sure where I read this but several hundred years ago a scientist made what he thought was the clearest water in the world. He then put it in the clearest glass container he could find. Today it is in a Museum somewhere and it is all clouded up. Glass is basically Silicon Dioxide and in what we call glass can also dissolve a little into a solution. My oddest experiment is with common dish soap. Some of them turn all Silver, Clad and even some Copper coins deep blue and it will not come off. I say odd because so many dish soaps are different forumlae that acquiring the same results repitiously is rare.
We did this once already and YOU showed me the photos! I don't have such photo's but two things A) What I said is scientifically valid. You just can't buck the laws of Thermal Dynamics B) I would need about 50 toned Morgans, a dipping soluition, a precision timer, and a microscope with a camera. I'd be happy to take donations and to publish all results. Ruben
I wasn't doubting you at all Ruben, I know your background. I was just curious if you actually had any pics. And yes I remember our previous conversations, but those weren't microsopic pics. That was just stuff you could see with the naked eye.
I didn't think you were doubting me. We can just put that sort of personal thing to the side Those photos you showed last time showed the crystylline structure of the metal. I was really impressed. Just like the tell told structure of rock after a meteror strike, the fast hammering under extreme pressure which a coin undergoes will make a surface crystilline structure and flow pattern. The coin under normal conditions ages and gets an errosion pattern. Dipping will do something very different to the structure. Those photos weren't microscopic? I'd have to admit they were much better than my eyes could ever see without a lens. Regardless of how great the magnification that you might need (another experimental factor I suppose) there will be some degree of magnification where one will see the damage by dipping and it will be distuigishable from the slower process of normal erosion. Such experimentation and cateloging of results would be worth funding for the purspose of enhancing the understanding and the ability of identifying coins. I have another question, however, about this overall. What condition existed where so many of the GCC Morgans from the tresury have almost no toning and original luster because CLEARLY they do, despite the severe age. If we could find that thread, you might add it to your resources section! With kind affection and love .... Ruben
I can't recall every showing any pics that would really fit the description your using. But I've posted some really closeup shots to illustrate my points in the past. Maybe you're confusing some pics somebody else posted Ruben - but I'll search thru the archives and see if I can find them. Now ya have me wondering :rolling: But I do understand what you mean, dipping does strip away metal and it can show on the coin if it wasn't done correctly and you know what to look for. But I've seen plenty of coins that I know were dipped and I couldn't see it - not to point it out to somebody anyway. But to answer your question - " What condition existed where so many of the GCC Morgans from the tresury have almost no toning and original luster because CLEARLY they do, despite the severe age." Somebody else already touched on that, and it's really not that hard to understand - especially if you take into consideration other comments I've made about the differences you can see in coins described as blast white in that they are not all the same. But simply put, the coins were stored in bags of 1,000 coins. The coins on the outer edges of the bags did tone, some of them beautifully so. But some of the coins in the center, that were completely covered up with other coins toned very little. This was because they were cut off from the circulation of air. It was blind luck really and conditions just happened to be just right. First of all the bags were stored in a vault where very little air circulated to begin with. Add to that that the coins were covered with other coins and bags upon bags and you have even less circulation, virtually none. And the coins were left that way for decades. So they toned very little. You also have to consider that thse coins were no treleased to the public until the '70s, and by then the collecting community had ready access to good quality coin holders and they knew about proper storage methods. So even after the coins were released, they weren't exposed to the air much and that helped keep any toning to a minimum. But if you were to compare any of those coins to another one made of exactly the same material, .900 silver alloy, that was struck today - you would see a quite noticeable difference in the color. And that difference would be due to toning on the older coins. Yes, they would still appear to be freshly minted white if you looked them by themselves. But once compared to a freshly minted coin, side by side, the slight grey color would be evident. You also have to realize that toning does not destroy luster at all. At least not until it becomes very, very dark and the oxidation reaches the point that it is literally eating the metal. That's why when you look at a toned MS coin it still shimmers in the light and has the cartwheel effect - the luster is still there. In fact a fully lusterous coin will tone more readily than one without luster. I've explained that before, it's because there is actually more surface of the metal exposed to the air due to the flow lines that create the luster in the first place.
Ruben & GDJMSP: Thank you for your discourse on the chemical effects on coins and toning. We all learned something today, at least I did. :thumb:
I have examined coins under a microscope both before and after a dip. I personally feel that there was not a significant difference, and I would be willing to wager a large sum of money, that if I dipped, and then let retone several coins, that NO ONE would be able to look at in under a microscope and tell the difference.
Carl, coin care is frequently used on copper coins, and it causes a shiny blue tint. Does your coin look almost like it is oily?
I should also mention, that it MAY be remotely possible to differentiate between a dipped an non-dipped coin, if the coin was examined in the exact spot, both before and after the dipping, and was studied extensively. Outside of that, a properly dipped coin, can not be labeled as such, if it was viewed under a microscope, but was not viewed before the dip.
No, you just don't know what your looking for or the magnification level you need to see it. As a chemical fact, the dipping process would leave a fingerprint that would be found by someone expert in looking for it. Set me up with about 40K and a lab, and in 6 months and at the end of the process I'll be able to nail every dipped coin under my nose, and I'd bet a billion dollars on that because there are many fields which do ***just*** that with metal compounds and alloys (not to mention more amazing stuff far beyound this simple thing). In fact, you can largely automate that with software, and many manufactoring processes do this. Ruben
