The Emerald Tablet is a cryptic and central piece of the Hermetica reputed to contain the secret of the prima materia and its transmutation. It was highly regarded by medieval alchemists as the foundation of their art and its Hermetic tradition. The original source of the Emerald Tablet is unknown. Although Hermes Trismegistus is the author named in the text, the text was first translated into Latin in the twelfth century. Numerous translations, interpretations, and commentaries followed.