From: La Paloma Mine, Zarza la Mayor, Cáceres, Extremadura, Spain


Formula: Fe3+24Al(PO4)17O6(OH)12·17(H2O)
System: Hexagonal
Colour: Yellow to brownish ...
Hardness: 3 - 4

It was first described in 1825 for an occurrence in the Hrbek Mine, Bohemia, Czech Republic. It occurs as a secondary phase in oxidized magnetite and limonite deposits. It also occurs in novaculites and in iron and phosphorus rich sediments.