The 1978 Eisenhower dollar is made of 40% silver. The rest of the composition is 60% copper. Another variety of the 1978 Eisenhower dollar exists as well. However, it doesn’t have silver in it.

If a solid copper stripe is present, one can conclude they are holding a clad Eisenhower silver dollar; but, if a solid silver stripe is visible, one can assume they are holding a 40% silver coin.