All dimes dated 1965 or later are clad and don't contain any silver. Quarters 1965 or later are copper-nickel except for bicentennials that are duel dated. The value of the coins are the value of the current price of silver.
Coins dated 1964 and earlier are made up of 90% silver. In the early 60's, there was a shortage of silver and coins 1965 and later were made using a copper nickle clad, using no silver at all. Coins pre 1965 are often worth 8 times their face value.
Anything before 1965 are silver coins,after silver clad. Clad coins have a copper ring around the edge that is noticeable, and weighs less than a silver coin. Silver coins also sound different than clad coins. It's kind of a higher pitched sound when dropped on table with other coins.