Rapid Toning Of Recent Lincoln Cents

Like many of us, I have a stash of pocket change in the center console of my car. While on lunch one day at work, sitting in my car, I opened the lid next to me and immediately noticed a beautiful Lincoln Cent that appeared to be on fire with a brilliant red-orange glow blending seamlessly into blue and purple near the edges. Picking it up for further inspection, obverse side up, it was a 2016. The reverse is just as evenly toned. As I pondered on how it toned so quickly, knowing full well that environmental conditions were the culprit, another drew my attention. Then another. All 2016 and 2017.

On my mind the rest of the afternoon, thinking that they must have came from the same bank, roll or what ever. Upon getting home I went through the three pound plastic coffee can that I threw them in, (and honestly, who doesn't?), low and behold there were many others. Vibrant shades of reds, orange, blue and purple. And again, all were current dates, the oldest thus far a 2014 of near full container yet searched to the bottom.

Environmental toning. Absolutely. But why only 2014 through 2018? To my knowledge the composition is unchanged at 97.5% zinc and 2.5% copper. Perhaps a new coating on the blanks? A cleaning type solvent used during the minting process? The questions are endless and remain very intriguing indeed!