Alunite

Named after the Latin word for “alum”, this mineral is also called “alumstone.” It was discovered in Latium, Italy, in 1824 and is formed by sulfuric acid solutions acting on rocks rich in potash feldspar. In Marysvale, Utah, it has been mined and treated to recover potassium and aluminum.

Mineral Photos courtesy of R.Weller/Cochise College