This 1984 nickel has what I would call "mushrooming" on the lettering around the rim. The rim is distinct, but the coin certainly shows some wear: Is this a die issue or wear on the coin? The effect is evident (but less pronounced) on the reverse of the coin as well. Here are close-ups:
I'd say it's a little of both in this case. The legends show wear, but the letters look to be broader than normal too. And if I understand the theory correctly as a die nears the end of its life the letters tend to get broader from wear to the die.
So does this go in the "take back to the bank & cash" box or the "Miscellaneous interesting Jeffersons to hoard" stack? (Since it qualify for the "pre-1964 Jefferson hoard" box nor the "Assorted BU Jefferson Hoard" box.)