Beryl cures asthma, jet strengthens loose teeth, heliotrope renders one invisible, and an amulet made of chrysolite drives away evil spirits-so writes, around the year 1100, the Breton bishop Marbod of Rennes in his famous Book of Stones (Liber lapidum).

Composed in elegant Latin hexameters, this didactic poem describes the medical and magical properties of sixty precious and healing stones, detailing their types, colours, and places of origin. Familiar gemstones such as diamond, agate, and sapphire appear alongside exotic, mythical stones drawn from ancient, pre-Christian sources.

By combining natural history, medicine, and magic, Marbod of Rennes created a key text of medieval intellectual culture. Widely copied, translated into the vernacular, and imitated, the Liber lapidum became the most widely read mineralogical compendium of the Middle Ages and beyond.

This volume presents, for the first time, a complete Latin-German edition of Marbod's Book of Stones, along with detailed explanatory notes that elucidate all its sections. The introduction traces the life and work of the author, explores the tradition of ancient and early medieval lapidaries, and shows how these shaped Marbod's poem.