Clean Or Leave Alone?

I would call that verdigris. Olive oil is safe, it is also very slow. Any damage that is under there will always be there, but it's worth a try. Depending on the date on the obverse of that coin, there are other ways to "conserve" it, but I don't recommend them on a key date coin.

Hi Newdavid

What is the date of the coin ? From the reverse pic the coin appears to be about VG-8 ,, if it is a common date there is little point to doing anything with it ,,

If it a Key date then a professional conservation is what I would recommend.

if its a Semi Key it may be worth trying to save it by a soak in EV olive oil,, although in most cases the results will not be outstanding.

Rick

What you will read and hear.....

Extra Virgin olive oil. Change out the oil every 2 weeks. A thorn from your rose bushes can be used to gently remove the green from the hard to reach areas.

The truth....

It will take forever. I tried it once. Left the coin in the oil for almost 2 years. What little that came off the coin was not worth the expense for the oil.

It may work for some coins, but sure didn't work for mine..

With the seperation between the jaw and cheek the coin will grade at Fine and being a semi Key perhaps even VF-20 even with the weaker Reverse.

Just keep in mind if you send the coin to be conserved it will be entombed in a conserved coin slab.

and there is no guarantee that the olive oil will have any affect on the degritis.

its a tough situation by grade the coins value is borderline for conservation and to valuable not to do something.

Rick

If you use Olive Oil or any such solution, the removing of that will require more substances and the end results will be a cleaned coin. If in fact it is a 31S it will still be worth a little even if cleaned.
This type of Copper damage is not reversible. Part of the metal has been chemically altered and the removing of that substance will also remove part of the metal leaving a pitted area. If you really want to try something, use Vinegar. The average Vinegar contains about 4% Acetic Acid which should neutralize that greent stuff.
If you are interested in what it is, it is a chemical reaction with something called AIR. When raw copper is exposed to the Oxygen in the air if forms Cu2O, a thin reddish layer. Then the moisture and Carbon Dioxide in the air attack the Cu2O to form [CuCO3-Cu(OH)2], known as Copper Carbonate, a greenish patina. Further if there is any SO or SO2 molecules floating around in the air due to coal burning organizations such as steel mills or power stations, This will combine with moisture to form H2SO3 or H2SO4 and furthrer attack the Copper Carbonate to form CuSO3 or 4, Copper Sulfite or Sulfate. Sorry for the chemical explanation but just comes from being a chem teacher to long.

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Originally posted by newdavid

Thanks Carl I actually have it listed on ebay right now. I wrote in the description that I believe it is corrosion. It looks as if some people jut do not care about problems. Bid is up over $60 right now. I feel bad that someone is in my opinion paying too much for it. The pics are clear enough for someone to see the problem.

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That coin is over $60!?!?! Geez, I think its time for me to sell my 31-S! It has no problems and is a RB MS60 !!! And I paid less than that for it many years ago....

I definitely do think that date is undervalued though. I do not think problem coins are undervalued.

Might fetch close to a $1000. Hey ya never know.