I've done some looking around and can't come to a conclusion. To start they are bicentennial S mints. I noticed a slight copper band on the rim which I thought meant I had two clad coins, however when I weighed them they came out to 24.93g and 24.57g which according to the internet is outside the margin of error for clads. They also pass the tissue test for silver, but I've never used that before so I'm hesitant about the result. I tried the sound test and it was inconclusive.
They weigh what a '76 40% Silver Ike should weigh (24.56g). More pics please. Obverse and reverse of each coin. But only if they are in focus.
The 40% silver Ikes ARE clad coins. 80% silver 20% copper outer layers clad to a 21% silver 79% copper core. the edge of the core can oxidize and darken allowing you to clearly se the three layers. The weight is right and they pass the tissue test and they have S mintmarks, they are almost certainly 40% silver Ikes. If you insist on further tests next comes either a specific gravity test or shoot it with and XRF gun.
Thanks for adding pics to the original post...they show that the coins are 1976-S Proof 40% Silver Eisenhower Dollars (which are all Type I).
