Pics would help. Even just the dates would. But I can tell you what S Proof half dollars are silver: 1968 to 1970: The halves from these San Francisco minted proof sets are 40% silver. 1976: 40% silver halves were minted in Bicentennial sets (the halves in 1975 and 1976 standard proof sets are clad; the silver proofs were sold in bicentennial silver proof sets that only had the dollar, half dollar, and quarter). 1992 to present: S Proof halves were minted in 90% silver in silver proof sets. (Kind of assuming you have Kennedy halves here, but the 1982 Washington 250th anniversary commemorative and the 1993 Bill of Rights commemorative half dollars are also 90% silver and minted in San Francisco.) Check the edge; it will be solid silver if you have a silver one (if you have one of the 40% silver clad 1968-1970 proofs or 1976 bicentennials, the edge will be a dark grayish color instead of copper). Other way you can tell is the weight (but requires a rather precise scale): copper-nickel clad halves weigh 11.34 grams; 40% silver clad halves weigh 11.50 grams; 90% silver halves weigh 12.5 grams.
good advice, troodon One cheap way of checking these would be to make a simple balance from popsicle sticks or pencils and balance them against a known (either silver or clad) half dollar
awesome call, Ken... I'd nearly forgotten it! the kleenex test is one of the easiest ways to tell. But you need a silver half and a 40% one to compare with
I bought a 1976 proof set that had a quarter with probably the nicest looking gold toning on the reverse.
If you don't know, the test is to put a kleenex tissue over the coin. If it looks white through the tissue, it is silver.
