Extreme Verd on George V coins

[Sword]

Described as "1921 Maundy set, verdigris to one side of all coins, otherwise extremely fine." by auction house. This must be the worst case of verd on 0.5 silver coins I have ever seen. Somewhat made my stomach cringe just looking at the photos. 

Anyone care to bid?

Edited July 25, 2019 by Sword

[PWA 1967]

Why would an auction house even try to sell them ,they want throwing in the bin and look awafull 

Agreed i have never seen anything that looks so bad even ones that have been dug up and corroded.

[JLS]

You could try strong acid on them -  I had a similarly ugly billion coin of 18th century Italy which was cleanable. There will still be heavy pitting on the surfaces though. 

[Sword]

2 minutes ago, PWA 1967 said:

Why would an auction house even try to sell them ,they want throwing in the bin and look awafull 

Indeed. You don't want them in your house for fear it might "infect" your other coins.

[PWA 1967]

Just now, Sword said:

Indeed. You don't want them in your house for fear it might "infect" your other coins.

Forget the coins i would be more worried that it might infect me 

[DaveG38]

One of those few occasions where the sale price is way below estimate? Usually its the other way round.

[copper123]

OMG cannot imagine anyone even a profesional cleaner would want them

Edited July 25, 2019 by copper123

[Sword]

31 minutes ago, DaveG38 said:

One of those few occasions where the sale price is way below estimate? Usually its the other way round.

No doubt. The estimate is £60 and there is no chance it will sell for that.

[Sword]

4 hours ago, PWA 1967 said:

Forget the coins i would be more worried that it might infect me 

Yes, but you might also turn a shade green if your best coins get infected by those things. Looks like the verd is dropping off readily onto the background piece of paper.

[VickySilver]

On the other hand, what is there to lose if the price is low enough? I think the usual attack would be correct:  mild detergent with lots of water and NO abrasion; then go with the acetone - I use the gentle cotton bud application with possible repeat applications & then followed by the aforementioned suds and water. 

This looks to be a chloride/PVC conglomeration on the surface and have used dilute ammonia to some effect on these before, but not before trying the other methods out...

 

PS - I do not subscribe to the "infective" capacity of such reaction as the conditions that caused it must be there for subsequent coin(s) to develop their  own versions....

Edited July 25, 2019 by VickySilver
complete thought process

[Sword]

6 minutes ago, VickySilver said:

PS - I do not subscribe to the "infective" capacity of such reaction as the conditions that caused it must be there for subsequent coin(s) to develop their  own versions....

I honestly don't know but can imagine that a speck of the green stuff can catalyse further verd development. 

[blakeyboy]

2 hours ago, copper123 said:

OMG cannot imagine anyone even a profesional cleaner would want them

You are right- I just asked the woman who does my mother's cleaning and she looked at me like I'd lost it.....

[ozjohn]

looks like the 1d., 2d., & 3d. were stored reverse exposed while the 4d. the obverse was exposed. Possibly a flat service as corrosion can be seen on the edge of all the coins as well. The coins must have been exposed to a very hostile environment It's  surprising the corrosion never effected the unexposed sides of the coins. There must have been a good seal between the coins and what they were resting on. As to what caused this ? This has been recently discussed before on these forums but this seems a pretty extreme case. As for cleaning I think the coins will be badly pitted after any attempt to clean them.

I'm assuming these coins were minted in 50% silver. I think they reverted to .925 silver at a later date.

Edited July 25, 2019 by ozjohn

[oldcopper]

13 hours ago, Sword said:

I honestly don't know but can imagine that a speck of the green stuff can catalyse further verd development. 

You'd have to have prolonged damp storage conditions there as well I would think.

[Michael-Roo]

 

And how about that duelling scar on the 2d obverse. I didn't know old Georgie had it in him.

[Sword]

2 hours ago, oldcopper said:

You'd have to have prolonged damp storage conditions there as well I would think.

Yes, a speck of "foreign" verd on its own might not be enough to cause problems. But verd, like other forms of corrosion does not develop evenly across the surface. Spots get bigger with time and would suggest that it is easier to form further verd on an existing spot rather than a clean surface. If a coin is stored in less than ideal conditions, it is not improbable that a verd speck could trigger off the process. These are all just speculations of course.

[Bernie]

I am no expert on silver coins, but verdigris on this scale is surprising from a high grade silver. Perhaps the coins rested on a copper surface. 

[ozjohn]

22 hours ago, ozjohn said:

looks like the 1d., 2d., & 3d. were stored reverse exposed while the 4d. the obverse was exposed. Possibly a flat service as corrosion can be seen on the edge of all the coins as well. The coins must have been exposed to a very hostile environment It's  surprising the corrosion never effected the unexposed sides of the coins. There must have been a good seal between the coins and what they were resting on. As to what caused this ? This has been recently discussed before on these forums but this seems a pretty extreme case. As for cleaning I think the coins will be badly pitted after any attempt to clean them.

I'm assuming these coins were minted in 50% silver. I think they reverted to .925 silver at a later date.

Typo " flat service"  of course should be flat surface.

[Peckris 2]

"Only" verdigris - what about that bloody great scratch on the 2d?

[craigy]

they remind me of some silver coins i find on the beach