Common salt (sodium chloride) is an invisible object for archaeological research, but the ancient texts, the history, the ethnography and our everyday life confirm that both Man and Animal cannot live without it. Salt is a primordial reference for humanity. This “fifth element” is universal in a double sense, diachronically and diatopically. How can archaeology and related disciplines or sciences approximate this soluble good, this “white gold”, this invisible past?

From the diatopic and diachronic perspective, common salt—with all its natural or artificial metamorphoses—has influenced humanity in the most diverse aspects. This is why, within a brief enumeration, the salt-related research themes are intriguingly various: explorations (hunting for salt), exploitation techniques, techniques to obtain different products, exploitation and use tools, transport and storage containers, human and animal feeding, conservation (meat, bacon, cheese, vegetables, green goods, fruits). The themes also include manufacture-related uses (including the construction of salt houses), mythology, religion, cult, rituals, beliefs, superstitions, mentalities, secret societies, magic, vows, curses, prohibitions, popular medicine, sexuality, economy, hide working, population, alchemical procedures, scientific and cultural representations, treatment of the deceased, barter, commerce, contraband, robbery.

On the other hand, the themes also include human and animal mobility, the attraction exerted on savage beasts, symbolic uses, folk literature (stories, tales, and proverbs) and cult literature, the control of salt resources, conflicts, strategic value, geographic perceptions, professions related to salt exploitation and uses, economic, legal and administrative regulations, vocabulary, toponymy, anthroponomy and the list can go on.

All these themes already constitute a study object for an impressive number of sciences, disciplines, or sub-disciplines, such as archaeology, heritage studies, history, ethnography, ethnoarchaeology, economic anthropology, food sciences, statistics, sociology, geology, mineralogy, geography, hydrology, botany, chemistry, medicine, pharmacology, ethology, theology, agronomy, symbology, linguistics, folklore studies, cultural studies, literary studies, hermeneutics, legal sciences, etc. Obviously, some themes must be approached only in an interdisciplinary vision.