Quite often among carbonate-hosted Zn-Pb(Fe) ore mineralization in Upper Silesia, Poland (e.g., Pieczonka, 2010). The material coded as the "UM" species comes from the Amelia mine, Wisconsin, USA.

One of a few mixed/intermediate-valence Fe-S natural compounds known. In the carbonate-hosted ore deposits these compounds occur as subsulphites (seeUnnamed (Fe Subsulphite)), sulphites (Unnamed (Fe Sulphite),Unnamed (Zn Sulphite)), pyrosulphites (Unnamed (Fe Pyrosulphite)), sulphoxylanes (Unnamed (Fe Sulphoxylane)), thiosulphates (compareUnnamed (Fe Thiosulphate II) andUnnamed (Pb Thiosulphate)).

These compounds are generally banded/radial/fibrous/spherulitic in form and have lowered reflectivity with growing sulphur valence. Compare alsoUnnamed (Fe Oxysulphide).

Upper Silesia, Poland: Botryoidal, with outer rim often recrystallized to pyrite and marcasite. Also as fibrous, syntiaxial intergrowths with sulfides and sulfates. May be oxygen-deficient.

Wisconsin, USA: As a mixture with pyrite-marcasite, that forms black patches. Analysis given in the Chemistry section concerns a homogenous area 40-50 microns in size. Determined thanks to the fact, that the valence state of S is related to wavelength shifts in the peaks for S in the electron microprobe analysis (EPMA).

Compareviaeneite;albertiniite (a sulphite).