and terms it salsugoterrae.

Pliny wrote that different substances were distinguished by the name of alumen, but they were all characterised by a certain degree of astringency, and were all employed for dyeing and medicine. Pliny wrote that there is another kind of alum that the ancient Greeks term schiston, and which "splits into filaments of a whitish colour". From the name schiston and the mode of formation, it seems that this kind was the salt that forms spontaneously