I went in to get rolled pennies and had to wait for them to get them out of the vault. As I was waiting, I noticed silver in the dime tray. I asked to buy $1 worth of dimes. I wasn't sure if they were silver, but at least one of them looked good.
In a lot of banks I go to, the trays are out of sight of the customer either in a drawer or under the counter, especially those heavily secured branches that have 2 inches of glass between you and the teller.