RAUENTHALITE
Class : Phosphates, arsenates, vanadates
Subclass : Hydrated arsenates
Crystal system : Triclinic
Chemistry : Ca3(AsO4)2 10H2O
Rarity : Very rare
Rauenthalite is a very rare mineral that was discovered at level -40 of the Gabe-Gottes vein, in the Ste-Marie-aux-Mines mine (Haut-Rhin), near another newly formed calcium arsenate : sainfeldite. Rauenthalite results from the dehydration of phaunouxite, which then loses a molecule of water. Its name comes from its discovery location : the Gabe-Gottes veins in the Rauenthal valley (Haut-Rhin). Rauenthalite occurs as small, irregular snow-white balls or irregular aggregates of very fine crystals, commonly associated with picropharmacolite. The size of these groupings does not exceed a few millimeters. Unlike other calcium arsenates, rauenthalite never adopts a fibroradiated arrangement.
Main photo : Rauenthalite from Clara Mine, Germany © Michael Förch
Rauenthalite in the World
Twinning
No known twinning for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 2
Density : 2.36
Fracture : Irregular
Streak : White
TP : Transparent
RI : 1.540 to 1.576
Birefringence : 0.030
Optical character : Biaxial +
Pleochroism : None
Fluorescence : None
Solubility : -
Magnetism : NoneRadioactivity : None