Hausmannite definitions

Hausmannite

1) Manganese mineral 2) Mineral
Found on https://www.crosswordclues.com/clue/hausmannite

Hausmannite is a complex oxide of manganese containing both di- and tri-valent manganese. The formula can be represented as Mn2+Mn3+2O4. It belongs to the spinel group and forms tetragonal crystals. Hausmannite is a brown to black metallic mineral with Mohs hardness of 5.5 and a specific gravity of 4.8. The type locality is Oehrenstock (Öhrenstoc...
Found on http://en.wikipedia.org/wiki/Hausmannite

hausmannite

a manganese oxide mineral (Mn2+Mn3+2O4) that occurs as brownish black crystals or granular masses in high-temperature hydrothermal veins and in ...
Found on http://www.britannica.com/eb/a-z/h/24

Hausmannite

Hausmannite is an ore of manganese. It has the formulae Mn2O4 and a relative hardness of 6.
Found on http://www.probertencyclopaedia.com/browse/HH.HTM