FLUCKITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Hydrated arsenates
    Crystal system : Triclinic
    Chemistry : CaMn(AsO3OH)2 2H2O
    Rarity : Very rare

Fluckite is a neoformed arsenate from mining operations. It was discovered in 1971 in the Giftgrube mine in the famous district of Ste-Marie-aux-Mines (France). It was named in honor of the mineralogist Pierre Fluck of the Louis Pasteur University of Strasbourg. It is a mineral which forms small prismatic crystals reaching 1.5 mm, grouped into spherolites up to 5 mm in diameter. It is easily recognized by its pale pink color due to a low cobalt content.

Main photo : Fluckite by Gabe Gottes Mine, Sankt Jakob vein, Neuenberg, Sainte-Marie-aux-Mines, Haut-Rhin, France © Stephan Wolfsried

Fluckite in the World

Fluckite is known at Sterling Hill (New Jersey) associated with other arsenates (pharmacolite, picropharmacolite, sainfeldite) formed like it by reaction of arsenic solutions with carbonates.

Fluckite in France

In France, fluckite is only known from the mines of Giftgrube, Sankt Jakob and Gabe Gottes (Haut-Rhin) near Ste-Marie aux-Mines, this is its type locality.

Right photo : Fluckite by Gabe Gottes Mine, Sankt Jakob vein, Neuenberg, Sainte-Marie-aux-Mines, Haut-Rhin, France © Uwe Haubenreisser

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 3.5 to 4
Density : -
Fracture : Irregular
Streak : White

TP : Translucent to transparent
RI : 1.618 to 1.642
Birefringence : 0.024
Optical character : Biaxial
Pleochroism : None
Fluorescence : None

Solubility : -


Magnetism : None
Radioactivity : None