Sorry about the pictures they don't show true images. I was checking some my mint purchases from the past, I purchased some 2009 US Mint Proof Sets in 2009 "Not Silver the blue box" Every one of the 4 Lincoln Cents in the plastic holder look like the proof "redish area" is starting to look more like a silver color mostly at the bottoms of the cents & more profound on the reverse. I also purchased some 2009 one cent proof sets looked at those and they do not look like these they look nice & red and mirror like. So are the cents in the proof sets Tonning, Damaged, Normal or Something else?? Thank You...
my 2009 Lincoln Proof Set is starting to tone also. I first noticed it last year and its progressively turned over the last year as well. I hope to get some good photos sometime.
Even though the holder is "sealed", there is a leak ( not unusual) that is allowing the change. Silver->gray>black (corrosion damage) on copper is usually due to Copper(II) and red colored ones by Copper(I) ions, along with air ( and the moisture therein). They made it 6 years to this point, but if they continue to be exposed environmentally, the process will continue. The process itself should slow down, but the effects will be accumulative. Toning is just an acceptable ( by many) level of chemical corrosion, and eventually damage levels will occur if continued.
Thank you for your explaination, and thank everyone else for your replies. How do I prevent them from getting any worse? Did this happen to these because they were in the box with the other coins in the set? The 2009 one cent proof sets by themselves in their own box do not show this Toning/Corrosion. Thank You...
They look GREAT to me, I don't consider toning "damage". If you want to halt the progression, move those proofs into some airtite capsules. They are toning because those mint holders are not air tight and the packaging may even outgas some vapors that contribute to the process.
Excuse_Me, If you can describe in detail how and where you are storing your coins, we can make suggestions on what you can change or do that will help protect your coins. Improper coin storage is usually the culprit.
I have a little room off the side of my house I use mostly for storage. It gets hot in the summer "no ac" in the winter around 50's-60's. I keep everything in zip-lock bags I get with my prescriptions finally I keep them all in thick clear plastic containers.
