Project Album Toning - 3 Year Mark

Folders are those inexpensive blue coin books with sections that fold over each other. Coins are not well-protected from the environment in them.

Yep, folder Hondo

There is such a thing called 'terminal toning' beyond which a coin cannot get any darker because the entire exposed surface has reacted with chemicals in the air.
Typically this takes a long time, but can happen rather quickly under certain conditions.
Remember the time 'back in the day' when smoking was considered (by some) to be cool, and nearly everyone did it?
That alone was responsible for much of the 'toning' seen on older silver coins.

Stinky!!!!

Is there actual sulfur in tobacco? I wonder what causes actual oxidation to the silver - or is it more so a film/stain? Like it does to one's lungs.

Pretty neat video!

Yes, there is some sulfur naturally occurring in tobacco. It gets atomized when smoked and forms silver sulfide in contact with silver coins.
But the worst thing about smoking processed tobacco, i.e. cigarettes, was the many non-natural additives added to them by the companies for various reasons, like glycerol for moisture retention and flavor enhancement, and sodium nitrate so the cig would keep burning while you were holding it.
That insidious trick made millions for the tobacco companies. There once were something like eighty different chemicals added to commercial tobacco products. I doubt it is much different today.

Another CCF winner ... thanks for sharing !