ALABANDITE

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal System : Cubic
    Chemistry : MnS
    Rarity : Fairly common

Alabandite is a manganese sulfide found in epithermal gold, silver and manganese deposits where it is associated with rhodochrosite, rhodonite, galena and sphalerite. It can be encountered anectodotically in meteorites. It owes its name to its place of discovery : Alabanda in Turkey. It is a mineral which most often massive or lamellar with perfect cleavage, quite rarely in cubic, cubo-octahedral and dodecahedral crystals of black color tarnishing in greenish brown. Its role as a manganese ore is very marginal due to its relative rarity.

Alabandite in the World

The finest specimens are octahedral crystals up to 10 cm from Merelani Hills in Tanzania (pictured right). It can be associated with diopside or tanzanite. We can also note the crystals encrusted with rhodochrosite of 20 mm from gold deposits in Romania (Baia-de-Aries, Sacarimb, Cavnic), as well as arborescent aggregates composed of pseudohexagonal crystals forming decimetric stalactites implanted on calcite (Broken Hill, Australia). Beautiful 15 mm octahedral crystals on rhodochrosite were also discovered in 2011 at Uchucchacua Mine in Peru (main photo © Carles Milan).

Alabandite in France

In France, superb millimetric crystals (5 mm) have been extracted from the manganese silicate deposits of Adervielle, in the Aure valley (Pyrenees).
Alabandite stalactite from Broken Hill, Australia - © Rock Currier

Twinning

The twins are known and parallel to {111}.

Fakes and treatments

No fake reported for this mineral species.



Hardness :  3.5 to 4
Density : 3.95 to 4.04
Fracture : Irregular
Trace : Dark green to brown




TP : Opaque
RI : Not measurable
Birefringence : None
Optical character : None
Pleochroism : None
Fluorescence : None


Solubility : Hydrochloric acid

Magnetism : None
Radioactivity : None