Sailaufite

sailaufite

arseniosiderite

kutnahorite

hausmannite

Images

Formula: (Ca,Na,☐)2Mn3+3O2(AsO4)2(CO3).3H2O
Valence: (Ca,Na,☐)2Mn3+3O2(As5+O4)2(CO3).3H2O
Hydrated arsenate, manganese-bearing mineral
Crystal system: Monoclinic
Specific gravity: 3.356 calculated
Hardness: 3½
Streak: Brown
Colour: Dark reddish brown to black
Luminescence: No fluorescence under UV
Solubility: Slowly soluble in hydrochloric acid
Environments

Hydrothermal environments

Sailaufite is a late-stage hydrothermal product in veins of manganese ore in rhyolite (HOM).

Localities

At the type locality, the Fuchs Quarry, Hartkoppe, Sailauf, Aschaffenburg District, Lower Franconia, Bavaria, Germany, sailaufite has been found associated with hausmannite, arseniosiderite, kutnohorite, dolomite, quartz, calcite and Mn-rich calcite. It occurs as strongly intergrown, dark red-brown to black tabular crystals, often forming mammillated coatings on calcite and arseniosiderite (EJM 15.3.555-564).
Aggregates of sailaufite are typically less than 0.5 mm in size; the mineral occurs as a late-stage hydrothermal product in veins of manganese ore in rhyolite (AM 89.249-253).
In a second occurrence in the lower parts of the quarry, sailaufite is associated with rhodochrosite, brandtite, tilasite and dolomite (CM 42.3.921-945).
Sailaufite from Fuchs Quarry - Image

At the Starlera Mine, Starlera Valley, Ferrera, Viamala Region, Grisons, Switzerland, sailaufite is associated with manganlotharmeyerite, tilasite and calcite in veinlets within massive braunite ore (AM 89.249-253).
Sailaufite from the Starlera Mine - Image

Back to Minerals