I was just wondering what has been done to these coins? Excuse my ignorance on the subject. They have a very yellow-goldish tint on both sides. (scanner) (Phone Camera
Any number of things will cause this. It is considered toning. Something has reacted with the coin to give them this toning. Could have been air quality, heat, moisture, album chemicals, artificial toning etc. It is very common.
It's hard to tell from your image, but they don't seem "shiny" enough to be plated. But I can't be sure. They appear to be circulated, so there isn't any value above face either way.
I am not very knowledgeable on toning. However, I could tell it was definitely artificial and not a natural thing. Personally I find them rather ugly.. haha Not sure why someone would want that color. :yes: