PARNAUITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous arsenates
    Crystal system : Orthorhombic
    Chemistry : Cu9(AsO4)2(SO4)(OH)10 7H2O
    Rarity : Uncommon to rare

Parnauite is a complex copper arsenate, admitting SO4 groups in its crystal structure. It is a secondary mineral present in the oxidation zone of copper deposits at the same time as many other secondary copper and arsenic minerals (malachite, spangolite, scorodite, chrysocolla, etc...). It was named in honor of the mineral collector John J. Parnau who made known the minerals of the Majuba Hill mine (Nevada), the type locality of parnauite. It appears in lamellar crystals, often gathered in rosettes or in flabelliform aggregates, green to pale blue in color. The parnauite also constitutes scales and compact encrustations.

Main photo : Parnauite from Majuba Hill, Vevada, USA © Uwe Haubenreisser

Parnauite from Clara Mine, Germany © Stephan Wolfsried
Parnauite from St Hilary, Cornwall, England © Steve Rust
Parnauite from Lubietová, Slovakia © Bohuslav Bures
Parnauite from Cap Garonne, Var, France © Pascal Chollet

Parnauite in the World

The Majuba Hill mine (Nevada) yielded 3 mm lamellar crystals, grouped in rosettes, considered to be the best known specimens. Parnauite is also present in several other American mines, but seems particularly common in the oxidation zone of copper veins in English Cornwall (Gwennap, Camborne, Saint-Hilary, etc.) and in German polymetallic veins (Clara Mine). It is also reported in Tsumeb (Namibia) and in Laurion (Greece).

Parnauite in France

In France, parnauite is described in sub-millimeter crystals at Cap Garonne (Var), at Kaymar (Aveyron), at Salsigne and at the Tistoulet mine (Aude), at Faymont (Vosges), at Vaulry (Haute-Vienne) and at the Hubac mine in Jourdan (Alpes-Maritimes).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 2
Density : 3.09
Fracture : Undetermined
Streak : Undetermined

TP : Translucent
RI : 1.680 to 1.712
Birefringence : 0.032
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : None