Article · Wikipedia archive · Last revised Aug 2, 2026

Xanthoxenite

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.

Last revised
Aug 2, 2026
Read time
≈ 1 min
Length
190 w
Citations
7
Source
Xanthoxenite
General
CategoryPhosphate minerals
FormulaCa4Fe3+2(PO4)4(OH)2·3H2O
IMA symbolXox1
Strunz classification8.DH.40
Crystal systemTriclinic
Crystal classPinacoidal (1)
(same H-M symbol)
Space groupP1
Unit cella = 6.7 Å, b = 8.85 Å
c = 6.54 Å; α = 92.1°
β = 110.1°, γ = 93.2°; Z = 1
Identification
Formula mass739.95 g/mol
ColorPale to brownish yellow
Crystal habitOccurs as platy crystals and as lamellar aggregates and crusts
CleavagePerfect {010}
Mohs scale hardness2.5
LusterEarthy (dull)
StreakWhite
DiaphaneityTranslucent
Specific gravity2.97 measured, 3.38 calculated
Optical propertiesBiaxial (-)
Refractive indexnα = 1.704 nβ = 1.715 nγ = 1.724
References234

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.4 It occurs associated with apatite, whitlockite, childreniteeosphorite, laueite, strunzite, stewartite, mitridatite, amblygonite and siderite.3

It has been found in Australia, Brazil, Portugal, Spain, Ukraine, and the United States. It was first described in 1920 for an occurrence in North Groton, Grafton County, New Hampshire.2

References

References

  1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. Xanthoxenite mineral data on Webmineral
  3. "Handbook of Mineralogy" (PDF). Archived from the original (PDF) on 2008-09-05. Retrieved 2010-05-15.
  4. Mindat.org