ARGENTITE

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal System : Cubic
    Chemistry : Ag2S
    Rarity : Uncommon

Argentite is a fairly rare silver ore from hydrothermal lead-zinc-silver and gold veins, mainly occurring in their cementation zone. It is associated with pyrite, sphalerite, galena, its dimorph acanthite, and many other silver minerals (polybasite, pyrargyrite, tetrahedrite); it is also a mineral accompanying gold in the epithermal veins, metalliferous emanations from volcanic activity. Its name comes from the Latin argentum, in reference to its chemical composition. Stable at high temperature, argentite transforms into acanthite below 179°C, a mineral with the same chemical formula which also borrows its forms : massive, tree-like, sometimes in cubo-octahedral crystals. It is a lead-grey mineral which quickly tarnishes black in air, characterized like many silver sulphides by a high specific gravity (7.2) and a low hardness of just over 2.

Argentite in the World

Automorphic crystals of argentite are rare and reach the centimeter, they are cubo-octahedra found on the deposits of Chañarcillo (Chile) and Monte Narba (Sardinia, Italy). The most beautiful samples sought by collectors are magnificent stalactitic aggregates of centimetric crystals on white calcite, exceeding 10 cm. They come from Freiberg (Saxony, Germany), Chihuahua and Guanajuato (Mexico).

Photo on the right : Acanthite pseudomorph after argentite from Imiter mine, Tinghir Cercle, Drâa-Tafilalet, Morocco

Argentite in France

In France, acanthite pseudomorph after argentite is found in microcrystals in the kaolin quarries of Echassières (Allier), at the mine of Le Rhun (Côtes-d'Armors), in the gold mine of Loperec ( Brittany), in the silver mines of Ste-Marie-aux-Mines (Haut-Rhin), at the Ste-Lucie mine (Lozère), at Peyrebrune (Tarn), etc...

Twinning and special crystallizations

Argentite may show polysynthetic twins on (111), but these are not visible to the naked eye.

Fakes and treatments

No fake or treatments identified for this mineral species.



Hardness : 2 to 2.5
Density : 7.2 to 7.4
Fracture : Sub-conchoidal
Trace : Gray




TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None


Solubility : Nitric acid, hydrochloric acid and ammonia

Magnetism : None
Radioactivity : None