HUREAULITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Hydrated phosphates
    Crystal system : Monoclinic
    Chemistry : Mn5(PO4)2(PO3OH)2 4H2O
    Rarity : Rare

Hureaulite is a secondary phosphate of granitic pegmatites. It comes from the alteration of primary phosphates such as triphylite or lithiophyllite, and usually accompanies other secondary phosphates (heterosite, eosphorite, etc...). Its name is dedicated to the locality of discovery : the Huréaux quarry near Limoges (Haute-Vienne). Hureaulite forms short prismatic crystals, sometimes tabular or isometric, frequently grouped in divergent bundles. The mineral is pale orange-pink to salmon pink in color, rarely brownish red or purple.

Main photo : Hureaulite from Pomarolli, Linópolis, Divino das Laranjeiras, Minas Gerais, Brazil

Hureaulite from Jocão claim, Conselheiro Pena, Minas Gerais, Brazil
Hureaulite from Pomarolli, Linópolis, Divino das Laranjeiras, Minas Gerais, Brazil
Hureaulite from Hagendorf pegmatites, Germany © Stephan Wolfsried
Hureaulite from Tip-Top Mine, South Dakota, USA © Gianfranco Ciccolini

Hureaulite in the World

The most beautiful hureaulite specimens certainly come from the Tip-Top pegmatite (South Dakota), with superb 3 cm crystals, or from the Brazilian mine of Criminoso in Minas Gerais, with crystallized aggregates weighing several kilos. Other South Dakota pegmatites have also yielded quality hureaulite crystals. Pegmatites from Hagendorf (Bavaria, Germany) yielded 3 cm pale pink to purplish pink crystals that rival those from Tip Top. It is also known in Portugal at Regada and at the Bendada mines.

Hureaulite in France

In France, hureaulite was discovered in the Huréaux quarry near Saint-Sylvestre (Haute-Vienne). There it forms bundles of divergent crystals of 1 cm, orange or purple, resulting from the alteration of triphylite.

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 5
Density : 3.15 to 3.20
Fracture : Irregular
Streak : White

TP : Translucent to transparent
RI : 1.637 to 1.671
Birefringence : 0.012 to 0.014
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : None