BROMARGYRITE

    Class : Halides
    Subclass : Bromides
    Crystal system : Cubic
    Chemistry : AgBr
    Rarity : Uncommon


Bromargyrite is a silver halide that forms a solid solution with chlorargyrite. These two minerals occur in the superficial oxidation zone of silver and argentiferous galena deposits. Its name is derived from its chemistry : bromine + silver (argyros in Greek). It is a pale yellow to orange-yellow, occasionally greenish, translucent, high luster, low hardness (2.5) mineral. The crystals are cubes, frequently modified, sometimes twinned on {111}, often grouped in parallel aggregates. Bromargyrite is associated with other silver halides and various secondary minerals of iron (goethite), lead (cerussite), silver or zinc, depending on the metals present in the deposit ; native silver is also common. It was occasionally a silver ore.

Main photo : Bromargyrite from Schöne Aussicht Mine, Dernbach, Germany © Dario Cericola

Bromargyrite from the Poullaba vein, Finistère, France © Guy Bernadi
Bromargyrite from Blue Bell Mine, California, USA © Bruce J. Kelley
Bromargyrite and malachite from Bisbee, Arizona, USA © Jason B. Smith
Bromargyrite from Mina Santa Barbara, Andalusia, Spain © Jean-Claude Dol

Bromargyrite in the World

Bromargyrite was very abundant in cubic centimeters in the oxidation zone of the gigantic Australian lead, zinc and silver mine at Broken Hill, and constituted a silver ore in the oxidation zone of Chañarcillo (Chile). It is also present in several American lodges, including Bisbee (Arizona).

Bromargyrite in France

In France, bromargyrite is known in small millimetric cubes in the lead-silver vein of Huelgoat (Finistère).

Twinning

Twins are known on {111} for this mineral species.

Fakes and treatments

No fake identified for this mineral species.



Hardness : 2.5
Density : 6.47
Fracture : Irregular
Trace : White to yellow



TP : Translucent to transparent
RI : 2.253
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None


Solubility : Ammonia and potassium cyanide

Magnetism : None
Radioactivity : None