SICKLERITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous phosphates
    Crystal system : Orthorhombic
    Chemistry : Li(Mn,Fe)PO4
    Rarity : Uncommon


Sicklerite is the manganese pole of a series that it constitutes with ferrisicklerite, the iron pole. It is a fairly rare secondary phosphate of lithium and manganese, formed by hydrothermal or meteoric alteration of primary phosphates (triphylite, lithiophilite, etc...) in granitic pegmatites. It was named in honor of the Sickler family, owners of the Pala deposit at the beginning of the 20th century. Sicklerite is unknown in crystals and occurs in masses or alteration rings surrounding masses of triphylite or lithiophilite. It is yellow-brown to dark red-brown in color, sometimes black.

Main photo : Black sicklerite from Stewart Mine, Pala, California, USA © John Sobolewski

Sicklerite in the World

Sicklerite is present in lithium pegmatites from California (Pala) and South Dakota (Custer Mountain). In Europe, sicklerite is found in pegmatites from southern Sweden (Varuträsk, Utö...), and Finland (Tammela, Eräjärvi). It is also present in various pegmatites from Morocco (Sidi Bou Othmane near Marrakech), Australia (Wodgina), and Canada (Tanco).

Sicklerite in France

Sicklerite is not present in the French underground.

Twinning

No known twinning for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.



Hardness : 4
Density : 3.2 to 3.4
Fracture : Undetermined
Streak : Light yellow to light red-brown


TP : Translucent to opaque
RI : 1.710 to 1.745
Birefringence : 0.035
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None


Solubility : Acids

Magnetism : NoneRadioactivity : None