MINIUM
Class : Oxides and hydroxides
Subclass : Oxides
Crystal system : Tetragonal
Chemistry : Pb3O4
Rarity : Uncommon
Minium is a secondary lead mineral formed by oxidation of galena or transformation of cerussite. It is uncommon due to its very specific formation conditions, which require both an alkaline environment and a dry, desert to semi-desert climate. It is a mineral known since Antiquity that is also found in industrial slag. The term minium originally designated cinnabar, often associated with red lead oxide. It is an opaque mineral with a dull luster which always occurs in earthy crusts or powdery masses of typical bright red color passing to brownish red, sprinkling galena or cerussite. It is locally an important lead ore.
Main photo : Minium from Broken Hill, Australia © Rob Lavinsky
Minium in the World
Twinning
No twin known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 2.5
Density : 8.9 to 9.2
Fracture : Undetermined
Streak : Yellow-orange
TP : Opaque to translucent
RI : 2.410 to 2.420
Birefringence : 0.010
Optical character : Uniaxial
Pleochroism : Strong
Fluorescence : None
Solubility : Hydrochloric acid
Magnetism : NoneRadioactivity : None