medieval mineralogy and figured stones

medieval mineralogy and figured stones It is true to say that during the Middle Ages no progress was made in mineralogy in Europe. What Aristotle (384–322 bc) had written in ancient Greece, classifying the minerals known then, remained unchallenged and unimproved into the nineteenth century. Not until well into the Renaissance were minerals and fossils denied occult, healing, or other supernatural powers.

Several theories were extant during medieval times to account for the varieties of ‘stones’ and their properties. Many of them refer to the ‘life’, a kind of inorganic force, that these objects may have had. Other ideas concerned the ‘petrific seed’, which had the power to condense water into mineral form, or to interact with emanations from deep in the Earth to produce mineral matter. Then came the theory of the ‘lapidifying juice’, a fluid that was thought to circulate through the crust of the Earth, the sea, and the atmosphere. This fluid might, it was believed, cause the development of mineral matter in the Earth or elsewhere, even in the human body—to produce kidney or other stones. Gems were though to have been produced from a simple crystallization of this fluid. Some writers regarded ‘stones’ as being either male or female and capable of producing young. Structures and markings, real or perhaps fanciful, were thought to indicate biological affinities and to be indicative of specific connections with living things. A further concept was that certain animals and plants produce gems or ‘stones’ in certain parts of their bodies, and that these, again, had special properties.

Healing or restorative powers were attributed to many minerals and rocks. Cures for a number of diseases, poisoning, or even mental conditions could, it was said, be made by administering mineral matter in one way or another. Several ancient compendia nevertheless list accurately the physical and chemical characteristics of many common minerals or rock types.

It was not until the sixteenth century that many of these notions were committed to print, but it is clear that many of the writers were then referring to beliefs held for many generations, if not centuries. Only at this time, also, do illustrations of minerals and fossils as we know them appear. The term ‘glossopetra’ was by then in use for objects of specific mineral character, such as colour, shape and symmetry, density, etc. They were held to be capable of growth while within the ground or while submerged in water, where they would acquire their characteristics. Clearly some of these objects were fossils, and to some were attached histories of their origin; devil's toe-nails, thunderbolts, and other fanciful names were applied to them. Some, such as the ‘thunder stones’ were, in fact, stone axes or other implements from prehistoric ages, and not uncommon in parts of Europe. The recognition of the true nature of such objects had to wait until the Renaissance, when scholars had access to, or made for themselves, collections of rocks, minerals, and fossils from many sources.

D. L. Dineley

Bibliography

Adams, F. D. (1938) The birth and development of the geological sciences. Dover Publications, New York.