Lanarkite - Encyclopedia
Class : Sulfates, chromates, molybdates
Subclass : Anhydrous sulfates
Crystal system : Monoclinic
Chemistry : Pb2(SO4)O
Rarity : Rare
Lanarkite is a rare lead sulfate from the oxidation zone of lead deposits that forms under basic conditions. It is also found in industrial slag. Its name derives from its locality of discovery : the Susanna mine, South Lanarkshire, Scotland. Lanarkite presents elongated crystals, with perfect lamellar cleavage, and frequently associated with other sulfates and carbonates, notably lead. It is gray, greenish-white or pale yellow in color. It is a very lead ore due to its rarity.
Main photo : Lanarkite from Susanna Mine, South Lanarkshire, Scotland, UK © Jeffrey Scovil
Lanarkite in the World
Twinning
Polysynthetic twins on [010] are known, but rare for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 2 to 2.5
Density : 6,92
Fracture : Splintery
Streak : White
TP : Translucent to transparent
RI : 1.928 to 2.036
Birefringence : 0.108
Optical character : Biaxial -
Pleochroism : None
Fluorescence : Yellow
Solubility : Nitric acid, potash
Magnetism : NoneRadioactivity : None