Clays represent one of the earliest exploited natural materials in human history. Their significance extends far beyond the realms of craft production and artistic practice, and, as we will see later on, they have played a central role in therapeutic, medicinal, and ritual activities throughout classical antiquity. Many of the most valued clays originate in hydrothermal environments, where elevated temperatures, mineral–rich waters, and active water–rock interaction create ideal conditions for their creation. In addition, therapeutic and ritualistic uses of hydrothermal mineral–rich waters during the classical period have been well studied (Annibaletto, Bassani, and Ghedini 2014; González Soutelo 2024; Bassani 2023, 2024), and many of the minerals extracted from these waters seem to have had their deep curative application (Mantovanelli 2014; Bassani 2014). This article examines several of the most prominent and widely employed medicinal clays described in classical texts. Through the lens of contemporary mineralogical and geological knowledge regarding their probable provenance and genesis, the study investigates the historical foundations of the therapeutic properties attributed to these materials and evaluates the extent to which such claims find support in modern scientific understanding. The accent was placed on potential origin of these clays in hydrothermal environments known and utilised in antiquity for therapeutic purposes, considering how such geological settings may have shaped the ritual practices and cultural meanings associated with their use.
Mila Cvektovic (Thu,) studied this question.