Supergel! (I had to look up the actual title. It's "It's Not Easy Being Me" by BethyM--an oldie but a cutie.)
How about this one?
On the bottom of Metropolis Harbor a nondescript piece of rock lay
anonymously amid the sand, weeds and debris. Inside the rock was a chunk of crystal, ominously green and speckled with tiny flecks of red. It lay there, timelessly, and the denizens of the ocean, plant and animal, lived their lives around it. It might lie there for a very long time. But it was still there.
Elisabeth
