I'll start off by saying I'm not a collector of coins, but I always had a habit of picking out coins that catch my eye when going through change, but I guess in a way that does make me somewhat of a collector LOL...
Anyways, I was counting coins in my change jar from over the years (was finally full & getting too heavy) & when I got to the nickels, this one caught my eye mainly because of how defined it is, then I noticed the year, it didn't make sense. Then when I got it under decent light, it has that copper/bronze-ish tint to it. It's beat up & has 100% been in circulation because I got it back in change from someplace, sometime ago and has been sitting in my coin jar for who knows how long.
I have no idea if it actually is a 1964 Special Strike or just a really old nickel & that tint/discoloration is just a result from age & being in circulation.