The Opal has the ability to give Luxen and hybrids a power boost. It's a good thing for them to have but very hard to find. The Onyx harms them by causing them grave amounts of pain. The Obsidian is used to kill an Arum ; the bad guys."It's a black opal --so rare that only a few mines can even unearth these babies. And it's only these kinds." - Luc page 271 1st paragraphWell, I am super pissed off about how the book ends, and I can write my own version of what I think should happen like.... the Arum helps Katy and blows her back outside the stupid @#$%! walls she is trapped behind UGH! I think if the next book is from Katy's point of view I don't want to know what goes on in that torture chamber and how will we know how the others are doing? I want to know how Dawson and Beth are doin ... RIGHT NOW !!!