Miersite - Encyclopedia

MIERSITE

    Class : Halides
    Subclass : Iodides
    Crystal system : Cubic
    Chemistry : (Ag,Cu)I
    Rarity : Very rare

Miersite is one of the very rare representatives of the mineralogical subclass of iodides. This mineral, in which copper can replace silver, forms a partial solid solution with marshite. It is found in the oxidation zone of silver-bearing polymetallic deposits, mainly in desert climates. It was named in honor of Henry Alexander Miers, Professor at the University of Oxford. Miersite forms tetragonal crystals of pseudo-octahedral appearance with striated faces, not exceeding one millimeter, aggregates and crusts, canary yellow in color.

Main photo : Miersite on cuprite from Rubtsovsk Mine, Russia © Knut Eldjarn

Miersite on azurite from Rubtsovsk Mine, Russia © Jordy Fabre
Miersite on azurite from Rubtsovsk Mine, Russia © Jordy Fabre
Miersite from Broken Hill, Australia © Judy Rowe
Miersite from Broken Hill, Australia © Henk Smeets

Miersite in the World

Discovered in Broken Hill (Australia), miersite is mainly a mineral from Arizona where it is reported in several deposits, notably in Bisbee. It was also discovered at the Rubtsovsk mine (Russia) on octahedra of cuprite or azurite, these are undoubtedly the most beautiful samples known.

Miersite in France

Miersite is not known in the French underground.

Twinning

A twin is known on {011}.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2.5 to 3
Density : 5.64
Fracture : Conchoidal
Streak : Yellow

TP : Transparent
RI : 2.20
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None

Solubility : Sulfuric acid

Magnetism : NoneRadioactivity : None