Akaganeite Field of view: 0,3 mm high Locality: Genna zinc smelter, Letmathe, North Rhine-Westphalia — Photo: Henk Smeets – tomeikminerals.com · CC BY 4.0
Akaganeite
A chlorine-bearing iron oxide-hydroxide that forms as pyrrhotite weathers; it is also one of the main corrosion products of iron.
Intro adapted from Wikipedia (CC BY-SA).
Akaganeite is an IMA-recognized mineral species in the halide class, with the chemical formula (Fe³⁺,Ni²⁺)₈(OH,O)₁₆Cl₁.₂₅·nH₂O.
It crystallizes in the monoclinic crystal system (space group I2/m). It is a member of the Coronadite structural group.
Key properties: specific gravity 3.52.
IMA symbol Akg, IMA status: approved, named in 1962.
Apparently formed from pyrrhotite by ferric-sulfate-bearing solutions (Akagané mine, Japan); an important constituent in some soils, and certain geothermal brines and in sea-floor nodules.
It is found associated with Pyrrhotite (Akagané mine, Japan); hibbingite (Hibbing, Minnesota, USA).
The name refers to the Akagané mine, Japan, its original locality.