Hibonite - Encyclopedia
Class : Oxides and hydroxides
Subclass : Oxides
Crystal system : Hexagonal
Chemistry : (Ca,Ce,La)(Al,Ti,Mg)12O19
Rarity : Very rare
Hibonite is a complex and rare oxide of strongly metamorphic rocks (marbles, pyroxenites, granulites) which keeps well in alluvium. It can also be found in certain meteorites. It owes its name to Paul Hibon who discovered the mineral in Madagascar. It forms flattened hexagonal prisms or sharp pyramids of a dark brown to black color. A few atoms of thorium replacing those of cerium sometimes make hibonite a weakly radioactive mineral. It is a mineral exclusively reserved for the collection, even if a few cabochons have been cut.
Hibonite in the World
Hibonite in France
This mineral is not present in the French underground.
Twinning and special forms
Fakes and scams
No fake recorded for this mineral species.
Hardness : 7.5 to 8
Density : 3.84
Fracture : Sub-conchoidal
Streak : Brown
TP : Opaque
IR : 1.790 to 1.807
Birefringence : 0.017
Optical character : Uniaxial -
Pleochroism : Not visible
Fluorescence : None
Solubility : Sulfuric acid
Magnetism : None
Radioactivity : Very low