Hausmannite from the Glückstern Mine, Friedrichroda – Botryoidal Aggregates on Manganese Ore

This Hausmannite specimen from the Glückstern Mine dump near Friedrichroda in Thuringia, Germany, shows a display surface that is almost completely covered by gray to dark gray, rounded to botryoidal aggregates. The numerous closely spaced aggregates form a distinctive, three-dimensional surface on the dark manganese ore.

Measuring 5.9 × 3.6 × 1.2 cm, this is a small cabinet specimen. The mineralogically interesting development is concentrated mainly on the display side, while the reverse is comparatively plain.

Rounded to botryoidal Hausmannite aggregates

The Hausmannite-bearing areas show a gray to dark gray coloration and are opaque. The surface of the individual aggregates is finely crystalline and shows a dull to locally weak luster under direct illumination.

Particularly characteristic is the rounded to botryoidal development. Numerous small to medium-sized aggregates occur closely together and cover large parts of the surface. Some are more strongly rounded, while others show a somewhat irregular nodular form.

The specimen was originally described as Hausmannite / Manganomelane. The term Manganomelane is an older collective name for dark manganese oxides or hard manganese ores and is therefore used here only as an additional historical designation.

Hausmannite from Friedrichroda, Thuringia

The Glückstern Mine near Friedrichroda is one of the historic manganese ore localities of Thuringia. Various manganese minerals were found in this mining district, including Hausmannite.

This specimen is interesting less for free-standing individual crystals than for its dense, rounded to botryoidal manganese ore development. This gives it a distinctly different character from well-crystallized Hausmannite specimens and makes it particularly interesting as a locality and ore specimen.