A United States ten-cent coin minted in 1964 and composed of 90% silver and 10% copper represents a significant point in American numismatic history. Prior to 1965, circulating dimes contained silver, but rising silver prices led to a change in composition to a clad metal (copper-nickel) to reduce production costs. The 1964 issue was the last year that dimes were primarily made of silver for general circulation.
These particular coins possess intrinsic value derived from their silver content, making them attractive to collectors and investors. Furthermore, they hold historical importance as symbols of a period when U.S. currency contained precious metals. This gives them a value beyond their face value, driven by the fluctuating price of silver and their collectibility.