What is the value of a 1970 US dime?

10¢ if you found it in change.

Dimes made in 1965 and later are made of copper and nickel, not silver, and are only worth face value. Check your pocket change for lots more of them. If you have a coin that appears to be silver it was probably plated for use in a bracelet or similar jewelry.

Note that dimes (and quarters, nickels, and halves) minted in Philadelphia before 1980 do not have mint marks.