jarosite

A native hydrous sulphate of iron and potassium, occurring in ocher-yellow rhombohedral crystals, and also in granular masses.

Varieties of this mineral in which the potassium is replaced by sodium and by lead have been called natrojarosite and plumbojarosite respectively.

An ocher-yellow mineral occurring in minute rhombohedral crystals. It is a hydrous sulphate of iron and potash.

A mineral with rhombohedral crystals, KFe33+(SO4)2(OH)6.