Unplated. Zinc is showing. Not silver nor aluminum. Also.. That is a 2005 Cent. Your title states 1985. Slow down and check your titles before you create your threads
Un-plated or de-plated? I'm guessing after it left the Mint. I have never run into any of these yet to make my own observations.
Welcome to CT @pinoyqt. It appears to be a zinc cent with the copper plate chemically removed, after it left the mint, so PMD, Post Mint Damage, not an error. In posting something like this, showing both sides are advised.