2002 Lousiana quarter back error?

[Patriot Relics]

I don't normally pay much attention to my change, but can any of you modern coin experts explain the toning on this? Looks like it's got a brass back?

 

Amazon Forum Fav 👍

Minelab PRO-FIND 35 Waterproof Pinpointer Metal Detector for Experts with Tone ID & Adjustable Sensitivity - Grab it through Amazon!

[galenrog]

Environmental damage. The cupronickel reverse oxidized. It happens.

Time for more coffee.