DIABOLEITE

    Class : Halides
    Subclass : Oxychlorides
    Crystal system : Tetragonal
    Chemistry : Pb2CuCl2(OH)4
    Rarity : Rare

Diaboleite is a rare secondary mineral from lead and copper deposits, typical of arid climates in chlorinated environments (closed lagoons, evaporitic basins and marine coastlines). It is also found in certain slags in neoformation. It is associated with other secondary lead minerals (cerussite, phosgenite, etc...) and very frequently with boleite. Its name comes from the Greek dia (distinct from) and boleite. It occurs in tabular crystals on {001}, with a square or octagonal silhouette, 2 cm maximum, commonly constituting subparallel aggregates of fine lamellae, of a deep blue reminiscent of boleite. it is also massive, in blue coatings or inlays.

Main photo : Diaboleite from Mammoth St. Anthony, Arizona, USA © Dan Polhemus

Diaboleite from Magallanes mine, Antofagasta Province, Chile © Enrico Bonacina
Diabolite from Penberthy Croft Mine, Cornwall, England © Steve Rust
Diabolite from the Lavrion slags, Greece © Stephan Wolfsried
Diabolite from The Gannel Smelter slags, Cornwall, England © Steve Rust

Diabolite in the World

The most beautiful diaboleite crystals come from mines in Arizona (Mammoth Saint-Anthony, Rowley), they are 2 cm square tablets. Good specimens have been discovered in Chile (Caracoles), in English Cornwall, in the Kopet-Dag Mountains (Iran), as well as in the Lavrion slags (Greece).

Diabolite in France

In France, diaboleite is reported in Crozet (Loire) in Poullaouen (Finistère) as well as in Cap Garonne (Var).

Twinning

A twin is known on {010}.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 2.5
Density : 5.41 to 5.43
Fracture : Conchoidal
Streak : Blue

TP : Transparent
RI : 1.850 to 1.980
Birefringence : 0.130
Optical character : Uniaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Nitric acid


Magnetism : None
Radioactivity : None