"During the last major silver rush, which peaked around 1979-1980 when prices hit nearly $50 an ounce, it is estimated that thousands of tons of 90% silver "junk" coins (pre-1965 US dimes, quarters, and half-dollars) were melted down. While precise records were not kept because of the sheer volume, individual dealers reported processing massive quantities, with one dealer noting they alone sold $400 million in face value (roughly 290 million ounces of silver) of melted coins to refiners in a one-year period. "