I paesaggi dell'allume

Abstract

The term alum has been mentioned since ancient times (for Strabo was στυπτηρία, for Columella and Pliny the alumen), also improperly, for a number of astringents and mordant saline substances. Alum is both a specific “chemical compound” and a class of chemical compounds. For their properties they were being used in the processing of fabric and leather as fixers of color. The specific compound is the hydraeted potassium sulfate (potassium alum), with the formula KAl3[(OH)6/(SO4)2]. The alunite comes from alteration mineral contained within volcanic rocks rich of aluminum, such as latites and trachytes, which under peculiar geological and volcanological conditions, generate characteristic association of minerals. In order to detect a possible quarries area in the Mediterranean basin, geological association of aluminous volcanic rocks and the presence of alteration minerals were the geological- mineralogical indicators used in this research.