1) Monoclinic mineral 
Rozenite is an uncommon hydrous iron sulfate mineral, Fe2+SO4•4(H2O). It occurs as a secondary mineral, formed under low humidity at less than 21 °C as an alteration of copper-free melanterite which is a post mine alteration product of pyrite or marcasite. It also occurs in lacustrine sediments and coal seams. Associated minerals include melant...