Manganochromite , Pyrrhotite Locality: Sätra Mine, Doverstorp ore field, Finspång, Östergötland, Sweden Dimensions: 25 mm x 25 mm x 30 mm According to the label (Excalibur): "submicroscopic intergrowths in pyrrhotite" Collection and photo Erik Vercammen — Photo: Erik Vercammen · CC BY 3.0
Manganochromite
Manganochromite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mn²⁺Cr₂O₄.
It crystallizes in the cubic crystal system (space group Fd-3m). It is a member of the Spinel structural group.
IMA symbol Mnchr, IMA status: approved, named in 1975.
From an extension gash vein in a metamorphosed hydrothermal pyrite deposit (Nairne deposit, South Australia); in a metamorphosed iron sulfide deposit in association with submarine felsic volcanism (Sätra mine, Sweden).
It is found associated with Pyrrhotite, rutile, diopside (Nairne deposit, South Australia); vuorelainenite, sphalerite, alabandite (Sätra mine, Sweden); troilite, daubreelite, alabandite.
The name refers to MANGANese in its composition, and relation to magnesiochromite.