green corrosion on coins

[joes2001]

I often see this green nasty corrosion on coins, especially on copper alloy coins. I read i think somewhere that they call this the "green death" or some such name. For example, here is an ebay 3 cent coin in unc condition with minute but obvious spots of this green stuff. Look at pic 3 (i think) where you can see it inside the date.

 

http://www.ebay.com/itm/1865-3-Cent-Peice-3CN-NGC-MS-62-3-Cent-Nickel-Error-Coin-/231125807359?pt=Coins_US_Individual&hash=item35d02bf0ff

 

I always thought this was envioronmental damage and not gradeable, but now i don't know whenever i see graded coins with it. I also saw it more visibly on an Australian large cent one time on both sides, but it didn't get a detail grade. It wasn't a rare coin either, so why wasn't it given a details grade? Does anyone know about this? I've been able to rescue some coins from this blue/green stuff with acetone, but it was probably because it wasn't on there long. I also read often that PVC damage is green/bluish. Is this stuff, like in the 3 cent example you can see, PVC damage? Why was it graded then?!? Sorry, i'm jjust confused.

[bsshog40]

Usually on copper, you will get "verdegris" and if too bad will cause a coin to be found enviromentally damaged. On the coin you have linked to, looks like possible pvc damage. The coin looks to possibly have been conserved before it was graded, more than likely by NCS with it resulting in an NGC holder. That's just my guess.

[joes2001]

Interesting. You might be right. I always run into that stuff, especially when I'm searching through world coins. One time I was at a shop and this couple brought a bunch of loose rare coins that they got somehow. They had a coin that was close to a thousand in its grade, and they were offered close to a thousand by the dealer. The crazy thing is that near the date there was a lot of that blue stuff! I asked the dealer why he offered so much and said isn't it damaged? He didn't seem to care though!

[jpcienkus]

Bobby, I agree that this coin was conserved or cleaned before it was sent in for grading, but I would think if NCS did it, they would have removed all the verdigris and not had it re-appear at a later date.

 

[bsshog40]

Bobby, I agree that this coin was conserved or cleaned before it was sent in for grading, but I would think if NCS did it, they would have removed all the verdigris and not had it re-appear at a later date.

The only reason I mentioned possibly conserved with NCS was because the coin looks too clean to me, and then being in an NGC holder. I'm not real knowledgeable with the series and conditions. Just a thought.

[jpcienkus]

Bobby, I agree that this coin was conserved or cleaned before it was sent in for grading, but I would think if NCS did it, they would have removed all the verdigris and not had it re-appear at a later date.

The only reason I mentioned possibly conserved with NCS was because the coin looks too clean to me, and then being in an NGC holder. I'm not real knowledgeable with the series and conditions. Just a thought.

 

Me neither Bobby. My post wasn't meant to challenge or offend. More along the lines that I would think NCS would get it all.

[bsshog40]

Bobby, I agree that this coin was conserved or cleaned before it was sent in for grading, but I would think if NCS did it, they would have removed all the verdigris and not had it re-appear at a later date.

The only reason I mentioned possibly conserved with NCS was because the coin looks too clean to me, and then being in an NGC holder. I'm not real knowledgeable with the series and conditions. Just a thought.

 

Me neither Bobby. My post wasn't meant to challenge or offend. More along the lines that I would think NCS would get it all.

Didn't take it any other way my friend! (thumbs u

[e1cnr]

The color and locations look more consistant to PVC rather than corrosion to me. There are little green balls all around the obverse periphery in the denticles.

 

Why was it slabbed? These are very small and we can see when blown-up 100x on the computer screen. Sometimes these areas show up after the coin was slabbed.

[joes2001]

I think PVC is a form of corrosion/damage, right? And it would be a part of the enviornment, at least where it was housed. I think NGC and other TPGs specify PVC damage when they know for sure or when it's obvious, otherwise probably just say environmental damage.