Got this out of our coin draw in the 60's. Not bent, just cracked. Then I picked it out of a bowl a few years back only to have it split in two. I haven't seen any cleanly broken nickels so I wondered about it's authenticity.
wow that is the first time i have ever seen that happen. can't tell if it is real or not. closer pics might help
This nickel is a typical dull gray worn Jefferson, between 4.9 and 5 gms (any green tint is an artifact of my photography). The inside is a lighter rough grey although a bit darker near one edge. Under a loupe the sharp edges look a little different than the inside.
What does the side of the coin look like? If there is a notch going around the whole coin it may have been a magic trick coin at one point. You see you get a coin and saw it down the middle to look like a bite mark then fasten a small rubber band around the coin in the notches. Then you pretend to bite off the other half of the coin and it'll fold down and look like you took a bite out of it then usually you pretend to spit it back and flip the half of the coin back up. Of course this may not be the case.
It happens sometimes that a coin will split like this, usually it happens before they get out of the mint and they are caught. Those that do get out may split during bagging and not go out in the same bag, or they split during rolling and are caught and rejected. Even if the whole coin gets out into circulation before if splits they tend to get lost or even thrown away by someone who thinks he just got stuck with a fake coin. Split coins with both pieces intact that haven't been messed with are rare. (Sometimes a mostly split piece turns up and someone pulls it apart to make a split coin leaving stress and tear marks on the metal. Yours looks like it should look)