My guess is it's artificially toned, in the non-deliberate sense. An artificial process is forced, in a much shorter timeframe than the natural one, and minor contamination on certain areas of the coin are capable of resisting the process for long enough to keep them from toning. With that said, stronger contamination could conceivably arrest the natural toning process long enough in the case of this relatively-lightly-colored coin, but it's highly unlikely.
Dip residue probably won't make the coin look like it does; in the rare cases where residue is left (and I've done enough experimenting to understand the process), it tends to be more sharply defined and less colorful. You have to *try* to leave residue from a dip - it's relatively soluble in water and rinses off easily. Furthermore, to leave such relatively dark residue, the coin would have to have been vary dark indeed to start and a dip sufficient to erase that much silver sulfide would have also killed the luster. Your coin does not show that. Look near the 4th left star. See the "speckled" appearance, on a line through the star and going up through the nose and eye? That appearance is what goes away in an overdipped coin - it becomes rather lifeless in almost any light.
To elaborate on the first sentence of this post: For my money, this coin was left exposed for a period - not deliberately - in an environment conducive to toning. My computer desk will do that to a Morgan in a few months, I think due to outgassing from whatever stuff was used to make the melamine from which it's constructed. Some minor contamination inhibited that process long enough to form the splotchy appearance. It would have had to sit too long to be deliberate; I think deliberate, short-timeframe artificial toning would have at worst created many smaller splotchy areas as opposed to a couple of large ones.
Keep in mind, the line between "artificial" and "natural" toning is a very gray one.
Oh, yeah, the solution: Only dipping the coin will make that go away. Acetone will not affect toning. Three seconds in thiourea will solve the problem, and I leave it to your judgment whether the coin's condition (circulated or not) and your own moral outlook makes that solution a viable choice.
Posted 03/14/2011 8:16 pm
