Book Haven discussion

Okay, I've never posted here before... but I need some help. I'm trying to find a book that I've been wanting to reread for the longest time that I read when I was in middle school, but for the life of me, I can't remember the title or author and it is driving me CRAZY.

All I can really remember is that it had something to do with a crystal and a group of kids/young adultsish and that the kids had some sort of powers and I THINK someone was trying to get the crystal for some reason... I also remember the paperback cover was like a purple and green and I think had a picture of the crystal on it...

I know this is a crazy long shot but I thought if I should ask anywhere, it would be here...

Any help would be much appreciated. Thanks!

I don't recognize that book, but I did find this page on a google search that has some good ideas for tracking childrens' books down.

http://www.oldchildrensbooks.com/look...

Thanks I'll have to try it out.

I wish I had more information on it... I think their powers were like... mental... maybe like mind reading? And something about the crystal going into someone's head or something... I don't know... I found out one of my other favorite books from middle school has a sequel and it kickstarted this memory and now it's just eating away... Ugh.