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
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