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Cacoxenite
Chemical Formula	Fe3+24Al(PO4)17O6(OH)12·17(H2O)
Species	Phosphates
Crystal System	Hexagonal
Mohs Scale	3-4
Specific Gravity	2.2-2.6
Color	Yellow to brownish yellow, reddish orange, golden yellow, deep orange, green; yellow in transmitted light
Streak	White
Luster	Silky
Refractive Index	n = 1.575 - 1.585 n = 1.635 - 1.656
Diaphaneity	Translucent
Cleavage	None
Fracture	Uneven
Crystal Habit：Acicular, radial, stellate
Geological Setting：Common accessory mineral in oxidation zone of magnetic and limonite iron ores, novaculites, rarely in iron rich sediments and soils.

Cacoxenite is an iron aluminium phosphate mineral with formula: Fe³⁺₂₄Al(PO₄)₁₇O₆(OH)₁₂·17(H₂O). It is associated with iron ores. The name comes from the Greek κ?κ?? for "bad" or "evil" and ξ?νο? for "guest" because the phosphorus content of cacoxenite lessens the quality of iron smelted from ore containing it.

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.