Pinakiolite - Encyclopedia

PINAKIOLITE

    Class : Carbonates, nitrates, borates
    Subclass : Borates
    Crystal system : Monoclinic
    Chemistry : Mg2MnO2BO3
    Rarity : Very rare

An extremely rare double borate of magnesium and manganese, pinakiolite is a mineral specific to metamorphic dolomites. Its name comes from the Greek pinakion (small plate, small board) in allusion to its crystals in the shape of fine rectangular black strips. It is associated with hausmannite and manganophyllite.

Main photo : Pinakiolite from Långban Mine, Sweden © OT. Ljøstad

Pinakiolite in the World

Pinakiolite is known from the Langban metamorphic manganese deposit (Sweden). It has also been described at Cain and Riddle mine in Nova Scotia (Canada).

Pinakiolite in France

Pinakiolite is not present in the French underground.

Twinning

Contact twins are common on {011} and can form crosses by interpenetration.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 6
Density : 3.88
Fracture : Undetermined
Streak : Brown-gray

TP : Translucent to opaque
RI : 1.908 to 2.060
Birefringence : 0.152
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Hydrochloric acid

Magnetism : NoneRadioactivity : None