Guanajuatite - Encyclopedia
Class : Sulfides and sulfosalts
Subclass : Sulfides
Crystal system : Orthorhombic
Chemistry : Bi2Se3
Rarity : Rare
Guanajuatite is a rare mineral, the selenite equivalent of bismuthinite and the dimorph of paraguanajuatite. It is a mineral from hydrothermal selenium deposits which is often found associated with clausthalite in gold-bearing veins. It owes its name to its discovery location : the Santa Catarina mine (Guanajuato, Mexico). Guanajuatite forms longitudinally striated acicular crystals of a maximum of 2 cm, as well as compact aggregates with a fibrous, foliated or grainy texture, of a dark bluish-gray color.
Main photo : Guanajuatite from Santa Catarina Mine, Guanajuato, Mexico © Eugene & Sharon Cisneros
Guanajuatite in the World
Twinning
No twin known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 2.5 to 3
Density : 6.25 to 6.98
Fracture : Undeterminated
Streak : Gray
TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None
Solubility : Aqua regia
Magnetism : NoneRadioactivity : None