What is "rozenite"

n. (context mineralogy English) An iron sulphide mineral with chemical formula FeSO₄·4H₂O.

Rozenite is an uncommon hydrous iron sulfate mineral, FeSO•4(HO).

It occurs as a secondary mineral, formed under low humidity at less than 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 melanterite, epsomite, jarosite, gypsum, sulfur, pyrite, marcasite and limonite.

It was first described in 1960 for an occurrence on Ornak Mountain, Western Tatra Mountains, Małopolskie, Poland. It was named for Polish mineralogist Zygmunt Rozen (1874–1936).