Up until 1964, most U.S. coins had 90% silver content. This included the dime, quarter dollar, half dollar and dollar coins. Five-cent pieces only had silver content during the latter years of World War II. Starting in 1965, the composition of most U.S. coins changed. Except for Kennedy half-dollars, silver was removed from the composition of circulation coins. Kennedy half-dollars minted from 1965 to 1970 also suffered a composition change, but while their silver content was reduced, they still had 40% of the precious metal. After 1970, silver in U.S. coins was limited to non-circulation coins such as Silver Eagles and certain coins struck for collectors and investors in coins. Over the decades, silver coins have gradually been removed from circulation by collectors. Today, it is nearly impossible to find a silver dime or quarter dollar in circulation. However, the following is one way of finding silver and silver-clad Kennedy half-dollar coins without paying premium prices to a coin dealer. The 1964 Kennedy half dollar contains 0.3617 troy oz of silver. Each silver-clad Kennedy half dollar contains 0.1479 troy oz of silver.
Go to the bank and ask to buy rolls of Kennedy half-dollar coins. These cost $10 per roll for 20 coins with a total face value of the same $10. For your convenience, you can request the same number of empty half-dollar rolls. Buy as many as you care to.
Remove the coins from each roll and stack them up.
Look at the side of the stack. You should see each coin edge-on. Most of the coins will have a copper-colored band through their gray-colored edge. Some will have a monotone gray edge.
Remove any Kennedy half dollar with a monotone gray edge and check the year appearing under Kennedy's bust. If the year is 1964, it is 90% silver. If the year is 1965 to 1970, it is 40% silver.
Roll up all Kennedy half dollar coins with a copper-colored band through their edge, making sure to place 20 in each roll.
Sell the rolled-up non-silver half dollars back to the bank for the same $10 per roll of 20 coins.
Take the silver and silver-clad coins you found and either keep them or else sell them to a coin store for a small profit.