UPDATE: What disease does this coin have, and WHAT WOULD YOU HAVE DONE?

[IGWT]

You'll see below a picture of the paleways on a 5c Shield proof. This coin is -- believe it or not -- the first I have ever received that has green (well, really aqua marine) gunk. The reverse has similar, though fewer, blotches along with some pitting on the devices that suggests a prior conservation effort.

 

What are these green measles, do you think the condition will worsen, and is this a candidate for conservation? Please give me your thoughts.

 

Edited to Add: See my next post on this thread -- how would you have dealt with this problem during the return-privilege period?

 

[gmarguli]

I've seen that on a lot of coins. It's like green crystals - looks like Miracle Grow. I'm not sure what it is. I don't think it is PVC, but it might be some form of it or something very similar. I've seen it on coins that were in old paper holders, so perhaps some chemical used in paper production?

 

Acetone will remove it without problem.

[TomB]

It looks to be either PVC or verdigris. Remember, nickels are 75% copper and verdigris forms on copper coinage.

[BankNote1]

I would also try acetone.

[supertooth]

I think it is verdigris. If it has gotten worse since the last time that you looked at the coin??, then I think it will continue to get worse. If that is true then I guess NCS would get my vote. However, before I conserved the coin, I would make real sure that you have no other alternative---other than treating it. After all, it is a proof shield five cent coin. Make sure you are right BEFORE you act. You do not want to be sorry later. Bob [supertooth]

[Hoot]

Most of the time that nasty stuff gets worse over time on nickels. I might try what Greg suggests (and I think his Miracle Grow idea is the best yet), but it's likely it'll require going to the chemical kettle to truly remove and stablize the stuff. I'd NCS it, but that's just me. They typically do a fine job with nickels. You can put it in the old velvet tray following NCS and see what toning it takes on and if der Grünen Tot grows back.

 

Hoot

[Newmismatist]

I would guesstimate a type of copper salt (verdigras) probably from being dipped and not rinsed properly. It is most likely active and will grow and cause severe pitting on the coin if not neutralized - I don't think acetone will neutralize it, as acetone removes organic contaminates and I think this is a chemical reaction that will continue to react even if it's treated with acetone

 

I'd suggest NCS

[IGWT]

Thanks, guys. Your help along with a bit of research on my end led me to conclude that the condition is formation of metallic salt; and, looking at the coin closely (not evident on the photo that I posted), there is pitting on the edge of many devices suggesting an earlier conservation effort.

 

To give you a little more information, when I wrote that I had "received" this coin, I meant that the coin had just come to me and that my 10-day return privilege had begun to run (a sight-seen purchase with seller holding my $ pending inspection). The seller has agreed with me that the coin has an impairment that will have to be dealt with sooner or later by NCS. He also acknowledged that he should have noticed the problem before sending the coin to me.

 

I have no experience whatsoever with NCS and certainly don’t know any of the personnel at either NCS or NGC. The seller, however, is quite familiar both. I proposed to the seller that I send the coin back to him, that he submit it to NCS/NGC on my behalf, and that we extend the return privilege for this period of time (with seller still holding my $). The seller declined my proposal. He agreed to extend the return privilege; but, for some reason, he insisted that I submit the coin to NCS/NGC directly. I don’t know the reasoning behind his position – if I had to guess, though, it would be his feeling that the coin was “mine” even though the return period was still running. From my perspective, I was buying the coin, not the problem, and he should have been willing to deal with NCS/NGC on my behalf.

 

So, I exercised my privilege and returned the coin. It was painful because it’s a very difficult (and expensive) coin that sits near the top of my want list. The seller will offer me the coin after conservation; but, he is reserving the right to change the price. Still, I think that I made the right decision.

 

The question up for discussion: What would you have done in this situation (as either the seller or the buyer) and why? CAUTION: THIS IS NOT A DEALER BASHING THREAD. THE DEAL FELL THROUGH EVEN THOUGH BOTH SIDES ACTED HONESTLY AND PROFESSIONALLY – WE SIMPLY DID NOT COME TO TERMS.

[cointagious]

I'm in the "doesn't matter what it is just get it off the coin soon" camp. Try acetone first as others suggest.

[IGWT]

Cointagious -- Did you read the updated post? I don't think that you would really suggest that I crack the coin out of its slab, make an amateurish attempt at conservation, and then try to exercise my return privilege. I agree with you, though, that removal of the verdigris (if removal is possible without causing too much damage to the surfaces) that it is better done sooner than later.

[supertooth]

Hello IGWT----- I sent my 23S Walker to NCS for conservation. The coin had dip residue---black and getting worse all the time. NCS did an "excellent" job. I guess noone knows that it could or would ever turn again?? But, if you did anything, NCS was the right move as per my previous thread. Now, as to the current decision that you have made. You are absolutely correct. The odds are that NCS will do a fine job---conserve the coin well. But---IT WILL DEFINITELY LOOK DIFFERENT---upon its return from NCS. If you have no experience at looking at NCS treated coins [pardon me---conserved coins], then you have without a doubt done the right thing. You could "love" the look or "hate" it----depending on what your eye appeal or philosophy dictates. You are better off letting him continue to "own" the coin. That way you still have "the choice". Bob [supertooth]

[cointagious]

I'm under the impression that verdigris would not be covered under any guarantee as it occurs naturally on the coin as opposed to PVC contamination..

 

It's slabbed? So what? If you are not skilled in coin conservation then, by all means, let a pro remove it but do get it off of the coin. This case looks problematic to me especially for resale.

 

As an aside, verdigris is only a problem over very long periods of time.

[BankNote1]

First post; IGWT didn't say that the coin was slabbed! Just what to do with the "gunk" on the coin. No brainer, get out the acetone! Acetone will not change the toning or hurt the surfaces of a coin. I rinse every raw coin I buy in acetone before sending it in to be graded. The only BB I have received in months is fron a 1927 Buffalo that I didn't rinse!!!

Second post; The coin being slabbed and with a 10 day return no less. This changes everything. No brainer send it back! If the coin was a "super deal" then that might change things again. If a super deal then I would get it off to NCS ASAP! NCS would dip in acetone and a Q-tip and like majic the coin would come back in a nice white holder!

With-out the details everything changes!!!

[Newmismatist]

My reply to your edited post: Return the coin immediately - do not pass go, - just return it for your refund - It's a problem coin, it's previously been cleaned (that's what the pitting is from) AND cleaning/conserving it another time may make it look dipped and washed out, no matter who does it - There are much better coins to buy and own.

 

BTW - What was the date?

[James_OldeTowne]

I have seen this on many high-grade coins, and believe it is corrosion caused by improper storage, much like PVC. The coin needs to be curated, but the danger is that the metal might be etched, resulting in permanent spots.

 

James

[IGWT]

Thanks, everyone, for your helpful comments.