A silver coin that has been dipped, will it most likely get an 'Env damage' or 'Imp. cleaned' or does it depend on the type of acid used and the duration? I am looking from a buyer's perspective when purchasing ungraded coins which look like they have been dipped in the past.
It should not get a details grade unless the surfaces of the coin has been in some way been damaged by the dip. Most graded coins of any age have been dipped at one point or another. It is a common practice for many dealers to dip their coin before submitting them for grading. There is nothing wrong with this unless it causes damage to the coin.
http://www.cointalk.com/threads/microscopic-comparison-of-luster.126215/ Check out the microscopic photos of the surface of a morgan in the thread above . Post 1 will probably be enough to show the peaks/valleys that produce lustre and the cartwheel effect. Each occasion that a coin is dipped, the peaks are reduced by the acid. As the distance between the peak and valleys becomes less, the lustre and the cartwheel effect also lessens , until they are almost the same height, and you get a shiny coin with no lustre, no cartwheel effect, and a damaged coin. The reduction is a combination of acid strength and time of exposure. Commercial dips are formulated for quick action. I dilute the stock solution by a factor or 1:5 or 1:10 with distilled water so I can better control the action when a dip is absolutely needed. Since it is a physical manifestation of chemical action, you can rinse off the acid and look at the surface anytime, and do it again . A diluted dip may take several trial to get what you want, but the chances of killing the coin are much less. There is no return to original point. Jim
Can you please define - look like they have been dipped. I ask that because if a silver coin has been dipped properly then it cannot be detected, except by deductive reasoning.
Sorry for not having been clear in the first place. In my understanding a coin that has been exposed for a longer period of time may look a bit dull and the toning may look unnatural, correct?
First of all if a coin has been dipped it won't have any toning because the acid strips away all toning. But yes that why I asked you to define things. If a coin is dipped for too long then it will look dull and washed out because the luster has been stripped away by the acid, but only when they have been dipped for too long. A coin can still be dipped and looked nearly perfect. That's what the other posters were explaining. How things turn out when you dip a coin does depend on 3 things, 1 - the length of time it is exposed to the acid, 2 - the strength of the acid, and 3 - the underlying condition of the coin (which is always an unknown). There are literally millions and millions of coins that have been dipped and then graded and slabbed by the TPG's. Dipping a coin can improve its grade or lower its grade, and sometimes drastically so in either direction, even when you do things correctly.
Doug, all, thanks for your input. Maybe it's time to post a picture what do you think of this coin's surface?
Dipping of circulated coins will in many cases get a code 92 not always but in some cases. BTW the rules do change with the condition of the coin between Uncirculated and Circulated IMO.
