Brownmillerite

minerals

portlandite

melilite

kalsilite

Formula: Ca2Fe3+AlO5
Multiple oxide, forms a series with srebrodolskite
Specific gravity: 3.76
Streak: Light brown
Colour: Reddish brown
Environments

Metamorphic environments

Brownmillerite occurs in thermally metamorphosed limestone blocks included in volcanic rocks (Webmin)

Localities

At Klöch, Südoststeiermark District, Styria, Austria, is associated with melilite, mayenite, wollastonite, kalsilite and corundum (HOM ).

Brownmillerite has two co-type localities, the Ettringer Feld and the Mayener Feld, both at the Southern lava flow, Bellerberg volcano, Ettringen, Mayen, Mayen-Koblenz, Rhineland-Palatinate, Germany. Here it occurs in thermally metamorphosed limestone blocks included in volcanic rocks, associated with calcite, ettringite, wollastonite, larnite, mayenite, gehlenite, diopside, pyrrhotite, hydrocalumite, grossular, spinel, chlormayenite, afwillite, jennite, portlandite and jasmundite (AM 50.2106, HOM, Mindat, Dana).

At the Hatrurim formation, Israel, occurs in high-temperature, thermally metamorphosed, impure limestone associated with spurrite, larnite and mayenite (HOM)

Back to Minerals