Went to the flea market and found a plastic cup encapsulated in Lincoln cent 77 Jefferson nickel 75-77 Roosevelt dime 65 to 68 can't figure out if they are silver dimes and if the Nickels have full steps need to know how to get these coins out of this plastic the 65 dime has no copper as far as i can tell
Silver coinage stopped in 1964. Anything dated after that is not silver, sorry. Not sure why you would want to remove these, I don't see anything that indicates they are worth more than face value.
Willie.. you keep stating this. Starting 1965 Dimes have a Clad Layer with a Copper core, not a Copper Clad layer. Look at any Dime minted from 1965 until today. They all look like the Dime you are showing us. No need to take those coins out. They will just get damaged.
Good luck getting them out of the acrylic undamaged, but your chances are very poor for doing that. I would put it in a sealed jar with acetone in case it is a low grade of acrylic ( do it yourself type), if the same a day later, lift it out with tongs or something and see if anything happened, other wise put it on the shelf to look at as alternative chemicals are very dangerous outside labs , IMO. Jim
Off metal errors have been found, with 1965 quarters on 1964 silver planchets, and the same with the dimes. In your case, it looks as if your coin was plated before being encased, and that's why you can't see the copper on the edge.
There was a time that these acrylic/coin art pieces were quite popular. I have one that is a paperweight on my desk. The artists wanted the entombed coins to appear as bright and shiny as possible so the coins would be plated and polished prior to being entombed in the acrylic. The plating hides the copper layer.