John L. Jambor, D. Kirk Nordstrom, Charles N. Alpers; Metal-sulfate Salts from Sulfide Mineral Oxidation. Reviews in Mineralogy and Geochemistry ; 40 (1): 303–350. doi: https://doi.org/10.2138/rmg.2000.40.6
“It is plain that almost all kinds of atramentum are made of Earth and Water. At first they were liquid and afterwards solid, and still they can be redissolved, by heat and moisture.”
Albertus Magnus (1205–1280) Book of Minerals (transl. D. Wyckoff, 1967)
The observation of “efflorescences,” or the flowering of salts, associated with periods of dryness in soils, in closed-basin lakes, in rock outcrops, and in mines and mine wastes has been noted since early antiquity. The formation of metal-sulfate salts, in connection with the mining of metals, was a phenomenon well known to the early Greek and Roman...