ROUBAULTITE
Class : Carbonates, nitrates, borates
Subclass : Uranyl carbonates
Crystal system : Triclinic
Chemistry : Cu2(UO2)3(CO3)2O2(OH)2 4H2O
Rarity : Very rare
Roubaultite is an extremely rare copper and uranium carbonate, known only in the oxidation zone of three uranium deposits, notably in Kantanga (Democratic Republic of Congo). It was named in honor of Marcel Edouard Roubault, Professor of Geology at the University of Nancy and author of the excellent "Détermination des minéraux des roches au microscope polarisant". Roubaultite occurs in small green lamellar crystals gathered in rosettes of 3 mm maximum. It is associated with becquerelite and soddyite on pitchblende in the process of alteration.
Main photo : Roubaultite from KOV Open cut, Kamoto, Democratic Republic of Congo © Italo Campostrini
Roubaultite in the World
Twinning
No twinning known for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 3
Density : 5.02
Fracture : Irregular
Streak : Undetermined
TP : Translucent to transparent
RI : 1.700 to 1.830
Birefringence : 0.130
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None
Solubility : -
Magnetism : NoneRadioactivity : Very strong