Books in the The Assalay Trilogy series

" It was a piece of soft white stone .Veins glittered through it like caught moonlight. One face was as smooth as new fallen snow; the other was engraved with a pattern of flowing lines. Gaia traced her fingers along the carvings. After a long time, she looked up at Mai.'What is it?' "All anyone knows about the old amulet is that it's a good luck charm that hasn't worked. And luck is about to turn worse, plunging Gaia and her brother Tal into undreamed-of dangers and strange discoveries that might change their world for ever...A fantasy adventure for readers of 11+, A Fragment of Moonswood is Volume One of The Assalay Trilogy