Looks like a two cent piece that belonged to someone with a lot of free time. Probably just a bored person grinding off one side. Still a very cool coin, most people don't even know that the USA ever minted a two cent piece
One of my middle school teachers had a 50 cent piece that he rubbed with his thumb. It looked the same on one side.
He thumbed that coin non-stop from 8am to 3pm through 7th and 8th grade.
I asked him why...and he said he had been doing it for years and it soothed his nerves while talking to us. That coin might have saved a few kids form getting smacked up side the head...who knows....