PHOSPHOFERRITE
Class : Phosphates, arsenates, vanadates
Subclass : Hydrated phosphates
Crystal system : Orthorhombic
Chemistry : Fe3(PO4)2 3H2O
Rarity : Rare to uncommon
Phosphoferrite is an iron and manganese phosphate which forms a series with reddingite, the purely manganiferous pole. It is a secondary phosphate of granitic pegmatites, in which it often constitutes an alteration product of triphylite. Its name is derived from its chemical composition : phosphorus and iron. Phosphoferrite is colorless to pale green and olive green, but changes to reddish-brown through alteration. Its crystals are tabular with a frequent appearance of pseudo-octahedra ; it is also found massive or coarsely fibrous.
Main photo : Phosphoferrite from Palermo, New Hampshire, USA © Scott M. Whittemore
Phosphoferrite in the World
Right photo : Phosphoferrite from Hagendorf, Bavaria, Germany © Uwe Haubenreisser
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 3 to 3.5
Density : 3 to 3.2
Fracture : Irregular
Streak : White
TP : Translucent to transparent
RI : 1,663 to 1,700
Birefringence : 0.036
Optical character : Biaxial +
Pleochroism : None
Fluorescence : None
Solubility : Acids
Magnetism : NoneRadioactivity : None