If the coins were minted before 1965, then one dollar's worth of silver coins contained .72258 oz. of silver. (Note that this will exclude cents and nickels except nickels minted from 1942 through 1945.) Nickels minted during World War 2 each contained .05626 troy ounce of silver (.11252 oz/$). Coins minted after 1964 for circulation contain no silver, except the Kennedy half dollars from 1965 through 1969. Each of these half dollars contain .14792 troy ounce of silver (.29584 oz/$. All of this assumes coins from circulation minted in the past century. There are numerous collector's-only coins made with silver, plus there are older coins with varying amounts and purities of silver in them.