| Xanthoxenite | |
| Category: | Phosphate minerals |
| Formula: | Ca4Fe3+2(PO4)4(OH)2·3H2O |
| Imasymbol: | Xox[1] |
| 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 |
| Cleavage: | Perfect |
| Mohs: | 2.5 |
| Luster: | Earthy (dull) |
| Refractive: | nα = 1.704 nβ = 1.715 nγ = 1.724 |
| Opticalprop: | Biaxial (-) |
| Streak: | White |
| Gravity: | 2.97 measured, 3.38 calculated |
| Diaphaneity: | Translucent |
| References: | [2] [3] [4] |
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, childrenite–eosphorite, 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]