(1857 Dime w/rainbow) - How does a coin tone like this?

FredF

Was browsing through the Heritage FUN catalog and saw the toning on this 1857 dime. This is lot 5469. I understand how rainbow toning can happen, my question is about the areas where it appears that there is no toning at all, surrounded by toning. It almost looks like something spilled on the coin at some point, after the coin had toned. It's currently in a NGC MS65 holder so I'm going to assume the toning is natural. I'm just curious how a coin can tone like that. I put an unedited version of the Heritage picture below, and then I put same coin with red boxes around the areas I'm speaking of.





Thx,
-Fred

ChangeInHistory

Cleaned and improperly rinsed?

MikeInFL

That looks to me to have been caused by something like oil being on the coin.

Flatwoods

<< <i>That looks to me to have been caused by something like oil being on the coin. >>



I agree. Instead of spilled after the toning occured, I think whatevwer it is was on there before the toning.
It kept that area from reacting with whatever caused the toning.

Barry

Could be album toning and some small flecks of debris such as paper flaked off.

Unknown

This content has been removed.

roadrunner

You see that spotty/patchy silver toning on a lot of original seated coins. The toning arc could have come later via album storage or even
added atop the original toning. But that could all be orig toning.

roadrunner

FredF

Thanks guys - I'm not a chemist so appreciate the insight.

-Fred

ricko

OR... it could have been stood upright in a small box with a fan and... oh never mind....Cheers, RickO