Pyrosmalite-(Mn) , Hedenbergite Locality: Broken Hill , Yancowinna County, New South Wales , Australia ( Locality at mindat.org ) Superb, maroon-colored crystals of this exceptionally rare pyrosmalite species perched on contrasting green crystals of hedenbergite. Formerly labeled johannsenite. However we recently were told that johannsenite from Broken Hill is rare at Broken Hill and requires confirmation. The crystals associated with the pyrosmalite here fall on the hedenbergite side of the fence. The older literature, and labels, referred to them as johannsenite, but more recent analyses have shown this is not the case This is an old, and very rarely seen, classic from Broken Hill 3.5 x 1.9 x 1.7 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Pyrosmalite-(Mn)
Pyrosmalite-(Mn) is an IMA-recognized mineral species in the silicate class, with the chemical formula Mn²⁺₈Si₆O₁₅(OH,Cl)₁₀.
It crystallizes in the hexagonal crystal system (space group P-3m1). It is a member of the Pyrosmalite, Clay structural group.
Key properties: Mohs hardness 4–4.5; specific gravity 3.06–3.19; Pearly on {0001} luster; optically uniaxial.
IMA symbol Pys-Mn, IMA status: approved, named in 1953.
Occurs as veinlets in the franklinite ore of a metamorphosed stratiform zinc deposit (Sterling Hill, New Jersey, USA).
It is found associated with Friedelite, bementite, willemite (Sterling Hill, New Jersey, USA); spessartine, manganoan tremolite, quartz (Takanosu mine, Japan); rhodonite.
The name refers to its high manganese content and relation to pyrosmalite-(Fe); pyrosmalite from the Greek for fire and odor, for the odor when heated.