Coin damage identification - Help [solved]

Hello,

I am relatively new to coin collecting and am organizing some silver coins that have come into my possession. On one of them (attached in photo), I noticed a kind of possible chemical reaction that left small green spots on one side. Does anyone know what this could be and, more importantly, how I can prevent it from happening? Thank you in advance.

The spots are most likely splatter from sneezing or coughing over the coin before storing it away. 

It is more likely PVC damage from being stored in PVC plastic sleeves. You need to remove it carefully with acetone and a cotton bud (blot donˋt rub) because the chemical left by the PVC is still reacting with the silver. Once the green is off (view under a loop) you may notice a discolouration or corrosion of the surface. 

Thank you both for your messages.

So, unless said pvc is removed with acetone there is a possibility that the reaction continues and spreads through the coin, even though it is now stored in a proper pvc free flip?

Carlos Mota

Thank you both for your messages.

 

So, unless said pvc is removed with acetone there is a possibility that the reaction continues and spreads through the coin, even though it is now stored in a proper pvc free flip?

 

 

Yes, it will take years and years, but I have seen pitting from pvc reaction. You never said which coin it is or how old, but that green part would have taken years and years to develop to this point already.

King

Carlos Mota

Thank you both for your messages.

 

So, unless said pvc is removed with acetone there is a possibility that the reaction continues and spreads through the coin, even though it is now stored in a proper pvc free flip?

 

 

Yes, it will take years and years, but I have seen pitting from pvc reaction. You never said which coin it is or how old, but that green part would have taken years and years to develop to this point already.

Right! Ill make sure to have it cleaned as soon as i properly learn how to do it. It's a 1953 portuguese commemorative 20 escudos “Financial Renewal” in case you were curious. It was given to me alongside several other coins who al came inside individual plastic flips from an extinct german bank, funny enough. Most likely said flips contained pvc as you noted, even tho this is the only coin that presented those green spots

Carlos Mota

King

Carlos Mota

Thank you both for your messages.

 

So, unless said pvc is removed with acetone there is a possibility that the reaction continues and spreads through the coin, even though it is now stored in a proper pvc free flip?

 

 

Yes, it will take years and years, but I have seen pitting from pvc reaction. You never said which coin it is or how old, but that green part would have taken years and years to develop to this point already.

Right! Ill make sure to have it cleaned as soon as i properly learn how to do it. It's a 1953 portuguese commemorative 20 escudos “Financial Renewal” in case you were curious. It was given to me alongside several other coins who al came inside individual plastic flips from an extinct german bank, funny enough. Most likely said flips contained pvc as you noted, even tho this is the only coin that presented those green spots

Well you are lucky they came from a bank, said plastic may have come from the 70s or 80s, so the coins could have been in them for 50 years - but (and like I said luckily for you) the bank would have stored them in the correct environment.

Moisture and sunlight are the catalysts for causing PVC to break down, personal collections on a shelf next to watered pot planks that experiences sunlight would have caked the coins in green oily goo. Likewise though they could have been stored for all that time not in PVC and only placed in the plastic recently in which case the tiniest bit of moisture could have reacted with the plastic. Either way better to remove the green.

N#11158

Nice coin, of course I was interested - I thought it looked Italian so I had a quick look for it there, with no luck.

King

Carlos Mota

King

Carlos Mota

Thank you both for your messages.

 

So, unless said pvc is removed with acetone there is a possibility that the reaction continues and spreads through the coin, even though it is now stored in a proper pvc free flip?

 

 

Yes, it will take years and years, but I have seen pitting from pvc reaction. You never said which coin it is or how old, but that green part would have taken years and years to develop to this point already.

Right! Ill make sure to have it cleaned as soon as i properly learn how to do it. It's a 1953 portuguese commemorative 20 escudos “Financial Renewal” in case you were curious. It was given to me alongside several other coins who al came inside individual plastic flips from an extinct german bank, funny enough. Most likely said flips contained pvc as you noted, even tho this is the only coin that presented those green spots

Well you are lucky they came from a bank, said plastic may have come from the 70s or 80s, so the coins could have been in them for 50 years - but (and like I said luckily for you) the bank would have stored them in the correct environment.

 

Moisture and sunlight are the catalysts for causing PVC to break down, personal collections on a shelf next to watered pot planks that experiences sunlight would have caked the coins in green oily goo. Likewise though they could have been stored for all that time not in PVC and only placed in the plastic recently in which case the tiniest bit of moisture could have reacted with the plastic. Either way better to remove the green.

 

N#11158

 

Nice coin, of course I was interested - I thought it looked Italian so I had a quick look for it there, with no luck.

Perfect, thanks for helping out.