xanthoxenite

{{Infobox mineral | name = Xanthoxenite | category = Phosphate minerals | boxbgcolor = | image = | caption = | formula = Ca4Fe3+2(PO4)4(OH)2·3H2O | IMAsymbol = Xox | strunz = 8.DH.40 | system = Triclinic | class = Pinacoidal () (same H-M symbol) | symmetry = P | unit cell = a = 6.7 Å, b = 8.85 Å c = 6.54 Å; α = 92.1° β = 110.1°, γ = 93.2°; Z = 1 | molweight = 739.95 g/mol | color = Pale to brownish yellow | habit = Occurs as platy crystals and as lamellar aggregates and crusts | twinning = | cleavage = Perfect {010} | fracture = | tenacity = | mohs = 2.5 | luster = Earthy (dull) | polish = | refractive = nα = 1.704 nβ = 1.715 nγ = 1.724 | opticalprop = Biaxial (-) | birefringence = | dispersion = | pleochroism = | fluorescence= | absorption = | streak = White | gravity = 2.97 measured, 3.38 calculated | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Translucent | other = | references = }}

Xanthoxenite is a rare calcium iron(III) phosphate mineral with formula: Ca4Fe3+2(PO4)4(OH)2·3H2O. It occurs as earthy pale to brownish yellow incrustations and lath shaped crystals. It crystallizes in the triclinic crystal system. It occurs as an alteration product of triphylite in pegmatites. It occurs associated with apatite, whitlockite, childrenite–eosphorite, laueite, strunzite, stewartite, mitridatite, amblygonite and siderite.