The story
By 1982 copper had made the one-cent coin a money-loser, so the Mint switched to a copper-plated zinc core — 97.5% zinc. The zinc cent's melt value sits under a penny, making it the rare US coin worth less than face in metal. Its economics have kept the kill-the-penny debate alive for four decades.
Zinc cents corrode dramatically if the plating is breached — collectors call the bubbling failures 'zincolns.'
