- 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 <internalXref urlencoded="natrojarosite">natrojarosite</internalXref> and <em>plumbojarosite</em> respectively.
- An ocher-yellow mineral occurring in minute rhombohedral crystals. It is a hydrous sulphate of iron and potash.
- A <xref>mineral</xref> with <xref>rhombohedral</xref> crystals, <xref>K</xref><xref>Fe</xref>33+(<xref>S</xref><xref>O</xref>4)2(O<xref>H</xref>)6.