MIARGYRITE

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal system : Monoclinic
    Chemistry : AgSbS2
    Rarity : Rare


Miargyrite is a rare silver sulfide, belonging to the “red silver” family. It is a metallic mineral that forms in hydrothermal veins of gold and silver. It has only exceptionally, in certain mines, constituted the main silver ore. It is most often embedded in a mass of sulfides, among which there are numerous silver sulfides. It is also a fairly common microscopic silver carrier of "argentiferous galenas". Its name comes from the Greek meion (less) and arguros (silver), because this mineral contains less silver than other red silver sulfosalts. Iron black to steel gray miargyrite, with dark cherry red internal reflections, is usually massive, very rarely in crystals. These are then thick tabular, with streaks parallel to [010] and [-101], and do not exceed one centimeter.


Main photo : Miargyrite from San José Mine, Oaxaca, Mexico © Jordy Fabre

Miargyrite from Neue Hoffnung Gottes Mine, Saxony, Germany © Stephan Wolfsried
Miargyrite from San Genaro Mine, Huancavelica, Peru © Stephan Wolfsried
Miargyrite from San José Mine, Oaxaca, Mexico © Jordy Fabre
Miargyrite from Neuenberg, Ste-Marie-aux-Mines, Haut-Rhin, France © Thierry Brunsperger

Miargyrite in the World

Beautiful crystals come from the Bräunsdorf mines near Freiberg (Saxony, Germany), Pribram (Czech Republic) and Baia Sprie (Romania). The most beautiful crystals, however, were extracted from mines in Peru (Huancavelica), Bolivia (Potosi), Mexico (Valencia mine, Guanajuato) and Chile (Tres Puntas).

Miargyrite in France

In France, miargyrite is known in microcrystals at Ste-Marie-au-Mines (Haut-Rhin), it is reported at the Mine des Anglais and at Aurouze near Brioude (Haute-Loire), at Vitrac (Puy-de- Dôme) and at the Porres mine (Var).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.



Hardness : 2.5
Density : 5.25
Fracture : Sub-conchoidal
Streak : Cherry red


TP : Translucent to opaque
RI : 2,720 to 2,800
Birefringence : 2.720
Optical character : Biaxial +
Pleochroism : None
Fluorescence : None


Solubility : Nitric acid

Magnetism : NoneRadioactivity : None