If they’re from after 1964 they were 40% silver also depends on the coin but if they’re half hours are 40% silver dimes, nickels and quarters shouldn’t be silver unless it’s a bicentennial but some bicentennial are silver, but not all anything anything before 1964 or 1964 is silver unless it’s a penny and if you have a 1965 dime or quarter that silver it’s worth a lot of money