It reminds me of my silver eagle set that years ago I pulled out of my safe and all the edges were toning and I couldn't figure out why until I realized that also in the safe was the abstract from my 160 year old house.
These Silver Eagles tone in unordinary ways. I wouldn't call them AT or NT. They are pure silver and will not tone the same way a 90% coin will.
Wait a second, every coin that has been put into a paper flip is AT? Coins have been stored in them for, well since I don't know when. Does that make them all AT?
I put coins into paper flips with the intent to preserve them and keep them from toning. A paper flip seals the coin with plastic on both sides if done properly. To put coins/metal in a known non-archival paper bag/envelope knowing it will have an effect on the items inside would be considered artificial toning.
The point being that unless you knew where and how they were stored. You don't have the claim of intent. You can judge the toning but can never on the secondary market prove intent. I definitely have a few that I put in a paper flip with intent/ as an experiment. Some tone some don't.
@Dougmeister. Very interesting experiment. I’m not usually attracted to colored or toned coins but that 2016 with a uniform soft brown tone is stunning. Thanks for sharing.