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 (Öhrenstock), Ilmenau, Thuringian Forest, Thuringia, Germany. Locations include Batesville, Arkansas, USA; Ilfeld, Germany; Langban, Sweden; and the Ural Mountains, Russia. The best samples have been found in South Africa and Namibia where it is associated with other manganese oxides, pyrolusite and psilomelane and the iron-manganese mineral bixbyite.
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Noun
1. a mineral consisting of manganese tetroxide; a source of manganese
(hypernym) mineral
(substance-meronym) manganese, Mn, atomic number 25

General Information:
 Chemical Formula:
Mn++Mn+++2O4
 Composition:
(Molecular Weight = 228.81 gm)
Manganese 72.03 % Mn
Oxygen 27.97 % O 
 Empirical Formula:
Mn3+3O4
 Locality:
Ilmenau and nearby at Orenstock, in Thuringia.
 Name Origin:
Named after the German mineralogist, J. F. L. Hausmann (1782-1859).
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
brownish black or grayish.
 Density:
4.7 - 4.84, Average = 4.76
 Diaphaniety:
Opaque
 Habits:
Massive - Granular - Common texture observed in granite and other igneous rock., Pseudo Octohedral - Crystals show an octohedral outline.,
 Hardness:
5.5 - Knife Blade
 Luminescence:
None.
 Luster:
Sub Metallic
 Streak:
brown
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B: (Kimia) hausmanit
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