In the year 1482, on a freezing, winter night in the midst of a heavy snowstorm, a solitary and penniless young man, fleeing from an abusive and violent home, sought refuge in a Benedictine monastery in the German province of Sponheim. This young man was the legendary Johannes Trithemius. Within a few months of his entrance into the monastery, he attained the position of abbot, and very soon after, he established himself as the friend and confidante of the Emperor and the trusted advisor on occult and spiritual matters to most of the German nobility. His students included Agrippa and Paracelsus. Trithemius was esteemed as the most learned man of his age, and wrote extensively on cryptography, alchemy, angelic magic, witchcraft, history, theology, and philosophy. An avid bibliophile, he collected thousands of volumes for his monastery's library, taking a special interest in arcane, obscure, and infamous books. This volume presents, for the first time in English, his fascinating compilation of treatises on the properties of magical amulets. These offer systematic and detailed descriptions of the design, properties, and powers of hundreds of images fashioned from stones of various kind. Also included is his Bibliotheca Necromantica (taken from his Antipalus Maleficiorum, or Shield Against Witches). This tract comprehensively lists and describes the various occult, necromantic, and magical volumes which Trithemius either possessed or had read, and offers an astonishing insight into the underground occult literature in circulation in Europe in the late Middle Ages.