Isso poderia ser Hans Bemmann "A Pedra e a Flauta" (originalmente publicado em alemão em 1983, mas traduzido em inglês em 1988).
Como eu tive uma experiência parecida lendo há muito tempo (ficando um pouco entediado e deixando no meio do caminho) eu não lembro de muitos detalhes, mas tenho certeza que havia um fauno / sátiro transformado em pedra.
Resumo de Google Livros :
In the country of Fraglund lives a young boy called Listener, a boy destined to inherit a precious stone and a magic flute which will help him to understand life's deepest mysteries. This is his story. As a young man, Listener is blind to the true value of his gifts. Before he can fully appreciate them he must endure many years of adventure and misadventure in his travels beyond Fraglund - with Gisa, evil mistress of Barlebogue castle; as servant to the minstrel Barlo and later as a minstrel himself; with the beautiful and ambitious Narzia, whose magic will commit him to the life of a faun; and with Arnilukka, in whose eyes he finds the colours of his mysterious stone. As he grows older, Listener slowly realizes that his life is caught up in a web of connections far deeper than he had at first presumed.