This stone looked nearly the same, but it wasn't. It was the Twisted Stone. And because of the small cracks embedded within it, the stone was broken, which caused wishes to be granted in unpredictable and undefined ways.
Jessica walked towards the spot where she usually met up with her friends before school. And as she approached Lucy Corinth (her ditzy friend), she took out the stone, completely unaware that it wasn't the same stone she inherited from her grandfather.