Brown sharp crystals of the rare iron-nickel chloride mineral from a little known locality in USA: Coalton, Boyd County, Kentucky, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Lawrencite
Lawrencite is an IMA-recognized mineral species in the halide class, with the chemical formula FeCl₂.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Scacchite structural group.
Key properties: specific gravity 3.16; optically uniaxial.
IMA symbol Law, grandfathered status — known before the IMA’s founding, named in 1877.
Found in iron meteorites, presumed to be a terrestrial alteration of meteoritic iron. Also as a volcanic sublimate.
It is found associated with Iron, molysite.
The mineral was named to honor John Lawrence Smith (1818–1883), American chemist, mineralogist, and student of meteorites, who discovered the mineral.