
Commonest of the sulphate minerals, gypsum is found in marine evaporites, in caves where the air is dry enough to allow it to be deposited and remain, at fumaroles, and in the oxidized zones of sulfide deposits on occasion. ... The selenite caves of Naica, Mexico. American Mineralogist: 12: 252-255. Himmel (1927) Zentralblatt für Mineralogie ...