HEINRICHITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Uranyl arsenates
    Crystal system : Tetragonal
    Chemistry : Ba(UO2)2(AsO4)2 10H2O
    Rarity : Very rare

Heinrichite is a hydrated arsenate complex of barium and uranium from the oxidation zone of uranium deposit. It is a mineral from the autunite group which derives from the alteration of uraninite (and therefore pitchblende) and accompanies other secondary arsenates, notably uranium (zeunerite, novacekite, etc...). It was named in honor of the American Eberhardt William Heinrich, Professor of Mineralogy at the University of Michigan. Heinrichite occurs in small tabular crystals with square or rectangular outlines, 2 mm at most, usually grouped in scaly aggregates, yellow to greenish yellow in color ; it fluoresces brightly in green-yellow under UV light.

Main photo : Heinrichite from Schmiedestollen dump, Wittichen, Germany © G. Franz Zöll

Heinrichite from Schmiedestollen, Wittichen, Germany © Stephan Wolfsried
Heinrichite from Schmiedestollen, Wittichen, Germany © Stephan Wolfsried
Fluorescent heinrichite from Schmiedestollen, Wittichen, Germany © Ko Jansen
Fluorescent heinrichite from Schmiedestollen, Wittichen, Germany © Volker Betz

Heinrichite in the World

Heinrichite is a very rare mineral which is practically only known from the polymetallic uranium veins of the Black Forest in the districts of Wolfach, Wittichen and Lahr (Germany). It is also found in coatings in the cracks of the rhyolitic tuff of Lakeview (Oregon).

Heinrichite  in France

In France, heinrichite is present at the Riviéral mine and at Rabejac near Lodève (Hérault). It is also reported at Echassières (Allier) as well as on the Kruth uranium deposit (Haut-Rhin).

Twinning

No twins known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2.5
Density : -
Fracture : Undeterminated
Streak : Yellow

TP : Translucent to transparent
RI : 1.573 to 1.605
Birefringence : 0.032
Optical character : Uniaxial -
Pleochroism : None
Fluorescence : Yellow-green

Solubility : -

Magnetism : NoneRadioactivity : Strong