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 Replies: 40 / Views: 6,149 |
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Valued Member
United States
254 Posts |
i have an 1837 half dime that was bright white years ago when I bought it. NGC au58 holder. later it started toning and acquired a sooty black color. now it seems to be slowly changing, part of the sooty black is now a blue-gray, part is a goldish peach color. how can this be? |
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Valued Member
United States
254 Posts |
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Pillar of the Community
Canada
4944 Posts |
Slabs are not air tight, it is probably the area you are storing your coins that is causing it to tone.
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Pillar of the Community
United States
5854 Posts |
CB gave one possible reason. Another could be the coin was treated with chemicals before it certified and the residues are causing the color change.
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Bedrock of the Community
United States
10523 Posts |
That's odd that it turned black and is now reverting to blue and gold. That is the opposite of normal tone progression.  1883-O Nut
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Valued Member
United States
254 Posts |
Here's what it looks like now  |
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Pillar of the Community
United States
8031 Posts |
Is it stored in a gun safe ?
Oregon coin geek.....*** GO BEAVS ! ! ! ***
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Bedrock of the Community
United States
12437 Posts |
If it was bright white when you bought it, someone dipped it before submission. A significant number of dipped coins are not properly dipped, i.e. dipped too long or not properly rinsed or both. Dip residue, typically composed of thiourea and sulfuric acid in a commercial dip, can darken a coin over time.
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Valued Member
United States
254 Posts |
Unfortunately, at one time the slab was stored with some rubber bands in a TupperWare container.
Edited by Scarp9603
01/27/2017 3:50 pm
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Pillar of the Community
United States
5240 Posts |
Climate change and humidity do a lot of things to where you stored your coins.
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Bedrock of the Community
United States
70143 Posts |
Agree most likely improperly dipped/rinsed before certification.
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Valued Member
United States
404 Posts |
Will NGC take a coin back and NCS conserve it if thats the case? |
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Pillar of the Community
United States
1499 Posts |
Contact with the sulfur in the rubber bands may have played a factor, but most of this problem is due to dipping with an improper rinse and neutralization of the dipping chemicals. I don't know if conservation can save this coin now. It's probably too far gone. This is one of the reasons why I like very old (10 + years) certification holders. If a coin has not gone bad in amount of time, chances are it's not going to go bad with proper storage. Barring an old holder, if you have the eye (experience and talent), you can very often tell if the toning on a toned coin is stable. If you are buying white colored silver coins in a new holder, good luck to you. I don't know of any way to predict if something bad is going to happen. The only silver coins that are often seen with no toning are Morgan dollars and many Peace dollars. Anything else that old and bright white has more than likely been dipped. The same advice applies to old red copper coins. Personally I don't like red copper for Indian cents and large cents. When I was dealer I got stuck on a couple of red large cents. They started to turn color in less than a year because they had been messed with to get the red color. That soured me on those coins. I won't buy them. Edited by billjones
01/28/2017 08:43 am
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Valued Member
United States
254 Posts |
The sooty toning appears to be getting lighter.
What's the prognosis for this coin?
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Valued Member
United States
294 Posts |
Send it back to NGC, and ask them to evaluate. |
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Pillar of the Community
United States
1499 Posts |
Quote:
The sooty toning appears to be getting lighter.
What's the prognosis for this coin? I don't know how the color could be getting lighter with the coin still in the slab and not subject to some sort of treatment. This is the first time I have ever heard of such a thing. I think that sending it to NGC could be a good move. It woulld be interesting to see what they think and are willing to do about the changes you have noted on this piece.
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Replies: 40 / Views: 6,149 |
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Posted 04/17/2013 5:45 pm
