In 1973, 74 and 76, the government issued two different S Ike dollars.  One was Copper-Nickel clad, and the other was 40% silver. In the holders or out of the holders, these look nearly identical.  Most people cannot tell a silver Ike from the clad Ikes. I know a trick, and I will share it with you - but only you. Put each coin side by side.  Lay a kleenex tissue on top of them. The silver coins will shine right through the tissue.  The clad will not. It is absolutely apparent.  You will know the clad from the silver. Since the silver Ikes are three times the price of clad Ikes, it is critical to know the difference.