Movie about teens who find a rock that gives them powers
Okay, so I'm pretty sure it was a 90's movie, as it was approx. 10 years ago I saw it, and I remember seeing it on the new release shelf at Blockbuster. The movie featured 4-5 kids who were in high school, and they wandered out into the woods to drink or smoke pot or something, and they discovered this blue/green (can't remember) rock, the rock gave them powers, and I don't remember much beyond that, except that one of the kids (I think something to do with one of the others with powers pushing him, or something to do with a picture of his parents), falls (or is pushed by the powers of another) off the roof of the high school. I've wondered this for a long long time now and I would really like to know the name of the movie. It was obviously sci-fi-ish, and seemed somewhat low-budget from the styling, so I'm guessing it was a "B"-list movie.
Any help much appreciated and thank you in advance.