…which I read about fifteen years ago.
The Earth (or whatever planet on which the story was supposed to take place) was shattered into thousands of fragments – some large, some small – and each fragment had a special “stone” or something that allowed that bit of planet to maintain normal gravity. (Some “ships” had their own stone, also). The queen (or whatever) in this book had a reptilian arm and magic powers. That’s about all I can remember.