Due to the escalating prices of copper, late in 1982, the Mint stopped producing copper Lincoln cents which weighed 3.1 grams. By 1983, the Mint had already transitioned over to a new zinc alloy, as it was much cheaper to produce Lincoln cents from zinc.
Zinc cents should have a weight 2.5 grams while copper cents should weigh about 3.1 grams. There is at least one known 1983 cent weighing 3.1 grams, which means it is composed of mostly copper. The 1983 copper cent is rare, since it is actually scarcer than the 1943 copper cents. The 1983 copper cent is just not publicized as much, but an example in any condition would easily sell for thousands of dollars in the coin market.