These particular pieces of currency, primarily dimes, quarters, half dollars, and dollars produced in the United States before 1965, contain 90% silver. An example is the pre-1964 Kennedy half dollar, identifiable by its silver content and lack of copper layers visible on its edge.
Their significance stems from their intrinsic metal value, which often exceeds their face value, making them attractive to collectors and investors. Furthermore, they represent a tangible piece of American history, reflecting the era when coinage was backed by precious metals and offering a hedge against inflation and economic uncertainty.