Pure silver coins, bars and US mint coins like Eagles are 100% silver and can be any year. However, common circulating dimes, quarters and halves from before 1964 were actually 90% silver, with 10% of other metals to make the coins more durable. That 10% of extra junk is why we call it junk silver.

Common circulating coins after 1964 don't have any actual valuable metal in them, if I remember correctly.

If you want to be sure to always have something people will trade for, get several pounds of dimes, quarters or halves in junk silver.

Pure silver coins, bars and US mint coins like Eagles are 100% silver and can be any year. However, common circulating dimes, quarters and halves from before 1964 were actually 90% silver, with 10% of other metals to make the coins more durable. That 10% of extra junk is why we call it junk silver.

Common circulating coins after 1964 don't have any actual valuable metal in them, if I remember correctly.