Abstract Fossils were credited with magico-medicinal properties in lapidary books written from the second century BCE onwards. The analysis of historical references to fossils in these ancient literary, geological, medical and magical texts has been named Cryptopalaeontology, a discipline that also includes discoveries of fossils at archaeological sites and the study of oral traditions. Theophrastus’ Perì líthôn (third century BCE), the four apocryphal Greek lapidaries ( Líthica Orphéôs , Orphéôs Líthica Kêrygmata , Socrátous Dionísou perì líthôn and Damigeron–Evax : second century BCE), Pliny the Elder’s Historiae Naturae, Dioscorides’ De Materia Medica (first century CE), Isidore of Seville’s Etymologiarum (seventh century) and Alfonso X’s Libro de las Piedras (thirteenth century) all contain frequent references to fossils. In this context, these works might be considered the oldest treatises on fossils ever written. The talismanic use of most of these fossils against a wide range of diseases was based on sympathetic magic. Only a few (e.g. Lapis Gagates, amber and Lapis Bitumen) survive in recent pharmacopoeia.