Characterization of an ancient ‘chemical’ preparation: pigments and drugs in medieval Islamic Spain

The analysis of the contents of an Islamic glazed ceramic pot found in Zaragoza (Spain) revealed an ancient ‘chemical’ preparation (11th century AD). The use of several analytical techniques (optical microscopy, scanning electron microscopy with X-ray energy-dispersive spectrometry and X-ray diffraction, and pyrolysis-gas chromatography/mass spectrometry) enabled us to identify mineral, organic and vegetal components: orpiment, a fig, and some grape seeds, together with a small amount of gypsum. The purpose of this mixture may have been for colouring because orpiment, the yellow sulphide of arsenic, has been used as pigment in painted decorations and manuscripts since ancient times. Nevertheless, since “yellow arsenic” was also one of the most common remedies in Arabic pharmacology and medicine, the components we identified may have been part of a medical treatment. Moreover, knowledge of the chemical composition of the contents of this pot provides a means of establishing the best way to conserve them.

► An Islamic ceramic pot revealed an ancient ‘chemical’ preparation (Spain, 11th c.).
► Chemical knowledge of the ingredients for history and artwork conservation.
► Ancient preparations are very difficult to recover and to be analysed.
► Orpiment and ficus carica as well-known products in the Islamic culture.
► We discuss the possible uses of these contents as pigment and as drug.