CHENEVIXITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Hydrated arsenates
    Crystal system : Monoclinic
    Chemistry : Cu2Fe2(AsO4)2(OH)4 H2O
    Rarity : Quite common

Chenevixite is a hydrated arsenate of iron and copper quite widely distributed in the oxidation zone of certain polymetallic hydrothermal copper deposits, but always in very small quantities. It accompanies other secondary copper minerals (arsenates and carbonates in particular). Its name was given to it in honor of the French chemist Richard Chenevix who carried out the first analysis of this mineral. It occurs in small tabular crystals (less than 0.5 mm), usually gathered in earthy microcrystalline encrustations or in spheroidal aggregates, sometimes acicular, yellow-green to dark green in color.

Main photo : Chenevixite from Christiana Mine, Lavrion, Greece © Fritz Schreiber

Chenevixite from Tsumeb, Namibia © Mariusz Oleszczuk
Chenevixite pseudo. after bariopharmacosiderite from Clara Mine, Germany © Michael Förch
Chenevixite from Clara Mine, Germany © Stephan Wolfsried
Chenevixite from the Tistoulet mine, Aude, France © Christian Berbain

Chenevixite in the World

Chenevixite is known from deposits in English Cornwall, Utah and Nevada, Australia, Chile, Mexico and Tsumeb (Namibia).

Chenevixite in France

In France, chenevixite is reported at the Tistoulet mine near Narbonne (Aude), at Kaymar (Aveyron) and at Cap Garonne (Var).

Twinning

No twins known for this mineral species. Can replace bariopharmacosiderite (pseudomorph) at the Clara Mine (Germany) in particular.

Fakes and treatments

No fake identified for this mineral species.


Hardness : 3.5 to 4.5
Density : 4.38
Fracture : Sub-conchoidal
Streak : Green-yellow

TP : Translucent to transparent
RI : 1.920 to 2.040
Birefringence : 0.120
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : None

Solubility : Acids


Magnetism : None
Radioactivity : None