SENGIERITE
Class : Phosphates, arsenates, vanadates
Subclass : Uranyl vanadates
Crystal system : Monoclinic
Chemistry : Cu2(UO2)2(VO4)2(OH)2 6H2O
Rarity : Very rare
Sengierite is a very rare hydrated vanadate of uranium and copper, it is one of these many secondary uranium minerals, first discovered in the deposits of Katanga, then sporadically in Morocco, Argentina and the United States. It is often associated with secondary copper minerals (malachite, chrysocolla) and uranium. It was named in honor of Edgard Sengier, Director of the Union Minière du Haut-Katanga (Democratic Republic of Congo). Sengierite occurs in coatings of hexagonal or square lamellae, flattened according to {001}, of yellowish green color, reaching 2 mm.
Main photo : Sengierite from Luiswishi Mine, Kawama, Katanga, Democratic Republic of Congo © Stephan Wolfsried
Sengierite in the World
Twinning
No known twinning for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 2.5
Density : 4.05
Fracture : Undetermined
Streak : Light green
TP : Transparent
RI : 1.760 to 1.970
Birefringence : 0.180 to 0.200
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None
Solubility : Acids
Magnetism : NoneRadioactivity : Strong