Anyone Know What Could Have Caused This 1991 Quarter Crazy Damage?

Given the photo posted, it appears the coin was exposed for a time to somewhat harsh environmental agents--which caused the 'corroded' look. That, along with some circulation wear.

to the CCF!

It looks like weak acid damage. Possibly from exposure to something like a soft drink. These are sometimes called Cup Holder Coins where a coin in a car is repeatedly exposed to spilled drinks. They may be stuck in the dried syrup for months or years. I worked as a lab tech for Coca-Cola and was amazed at just how strong phosphoric acid was. You had to be really carful when sampling and dissolving caffeine in phosphoric acid as it would damage almost any equipment exposed for very long.

Must be some chemical with maybe another coin next to it too?

Maybe they just kept their change for no reason. I do it. I never use change. Goes from my pocket to my cup holder in my truck, to my desk to check and then in a tub. Not a bath tub...lol Although

I usually split it between my 2 kids around xmas time so they can buy gifts for each other. My dad used to keep all his change in one of them old glass water jugs and then when something came to town, we liked wrestling, WWF back then, I would roll it up and we would go. Wish I still had all those wheat cents I found back then.

Anyway, some people just toss their change in something for no reason just because its change, not because its rare.

Possible cup holder coin damage from sodas and neglect.