Today as I opened a Virginia P Mint Sewn Bag from the US Mint I discovered about 6 coins that the reverse is dull, kind of lust faded that look like zinc and or some porous content was poured on top. Does anyone know what this is? It is a n error of dyes or? Is it an error? I am clueless any help is appreciated. The Obverse although is just like a normal BU coin shine and nice. Thank you for any help.
It is due to the lack of climate control in the location where the bags were stored. The surface of some of the coins (not all) touching the bag are affected by their proximity to the dampness. ~ Chris
Oh, Welcome to Coin Talk. Seems odd that if it was from storage the damage would be on just the reverse.
I bought a lot of the $25 SQ bags from the Mint as well as from sellers on eBay. Those bags direct from the Mint were pristine uncirculated coins, but some of the bags from eBay contained a few coins just like this. The only thing that I could conclude was that the side of each coin that touched the canvas bag was subjected to the dampness in the room where the bags were stored. ~ Chris
Yes But I did get the bag from the US Mint and were stored in my safe for all these year. Safe has a humidifier and a lot of Silica gel pad and I have many other coins but never run in to this. the other 94 coins that were in the bag they are pristine BU except the reverse of these 6 that has this surface that seems a bit porous with a grayish layer of powder on on the reverse when the same obverse coin is pristine BU. This leave me still clueless of what are these 6 coins. Is there a name for this type of appearance, defect or error if any?
Why would a safe have a humidifier? Would that not defeat the purpose of the gel pad? Just asking Unless you kept cigars in there also
The appearance is called environmental damage. If you go through the steps of the minting process, there really isn't a reasonable explanation of how this could be mint induced. An improperly annealed planchet would show the effect on both sides. However, the 75%Cu25%Ni clad layer can show discoloration when exposed to numerous environmental conditions. People post these all the time. Exposure to moisture or some other reactant after it left the mint (including the time period before you put it into your safe) seems to be the most likely explanation
