Images
Formula: Fe3+24AlO6(PO4)17(OH)12.75H2O
Hydrated phosphate containing hydroxyl
Specific gravity: 2.2 to 2.6
Hardness: 3 to 4
Streak: Yellow
Colour: Yellow to brownish yellow, reddish orange, golden yellow, deep orange, green; yellow in transmitted light
Solubility: Readily soluble in acids
Environments
Pegmatites
Sedimentary environments (rare)
Hydrothermal environments
Cacoxenite is a common secondary mineral found in oxidised zones of phosphatic
magnetite deposits, in iron and manganese bearing
novaculite, in phosphate-rich pegmatites, and rarely in iron-rich sediments and soils
(Mindat, HOM). Associated minerals include dufrénite,
rockbridgeite, beraunite,
strengite, wavellite,
magnetite and limonite
(HOM, Mindat).
At Tom's, Moculta and St John's phosphate quarries in South Australia, cacoxenite has been found replacing small
pyrite crystals (AJM 17.1.12).
The type localityis the Hrbek Mine, Svatá Dobrotivá, Central Bohemian Region, Czech Republic.
At the Isom Avants prospect pit in Polk County, Arkansas, USA, cacoxenite has been found in brecciated
limonite-stained novaculite with fracture
fillings of limonite. The cacoxenite occurs lining cavities in the
limonite (AM 51.1811-1814).
At the John A Logan mine, Cripple Creek Mining District, Colorado, USA, cacoxenite occurs in partly oxidised
orthoclase - quartz -
pyrite rock, following earlier
strengite and followed by a member of the
rockbridgeite family (MinRec 36.2.164).
At Antwerp, Jefferson county, New York, USA, cacoxenite occurs on earthy
hematite (Dana).
Back to Minerals