Hausmannite

(mineralogy) Mn₃O₄ Brownish-black, opaque mineral composed of manganese tetroxide.

A mineral with composition Mn²⁺Mn₂³⁺O₄. Hausmannite is most frequently massive-granular and possesses one perfect basal cleavage. The color is black, and streak dark brown. Hardness is 5.5 on Mohs scale, and the specific gravity is 4.81. It is an occasional ore of manganese, and it most frequently occurs in metamorphosed sedimentary manganese ore deposits, such as some small deposits in central Sweden and inthe Central Provinces, India.

The noun has one meaning:

Meaning #1: a mineral consisting of manganese tetroxide; a source of manganese

Hausmannite
General
Category	Oxide mineral
Chemical formula	Mn2+Mn3+2O4
Identification
Molar mass	228.81
Color	Brownish black, Grayish.
Crystal habit	Massive - Granular - Common texture observed in granite and other igneous rock. Pseudo Octahedral - Crystals show an octahedral outline.
Crystal system	Tetragonal (4/m 2/m 2/m) Space Group: I 41/amd
Cleavage	[001] Perfect
Fracture	Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Mohs scale hardness	5.5
Luster	Submetallic
Streak	dark reddish brown
Specific gravity	4.7 - 4.84, Average = 4.76
Optical properties	Uniaxial (-), e=2.15, w=2.46
Other characteristics	non-radioactive, non-magnetic, Non-fluorescent.

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.

Crystal structure of hausmannite

External links

• Mineral galleries
• Mindat
• Webmineral

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v • d • e Manganese minerals Borates Sussexite · Tusionite Carbonates Ankerite · Kutnohorite · Rhodochrosite  · Manganoan Calcite Oxides Simple Hausmannite · Manganite · Manganosite · Nsutite · Pyrolusite Mixed Birnessite · Bixbyite · Ferrocolumbite · Ferrotantalite · Galaxite · Jacobsite · Manganotantalite · Psilomelane · Romanèchite · Tantalite · Todorokite · Umber Phosphates Childrenite · Graftonite · Lithiophilite · Natrophilite · Purpurite · Triplite · Triploidite · Zanazziite Silicates Babingtonite · Bixbite · Braunite · Brownleeite · Calderite · Chloritoid · Eudialyte · Glaucochroite · Jeffersonite · Knebelite · Ottrelite · Piemontite · Pyroxferroite · Rhodonite · Spessartine · Sugilite · Tephroite · Zakharovite · Zircophyllite Sulfides Alabandite · Hauerite · Rambergite Other Axinite (borosilicate) · Geigerite (arsenate) · Manganese nodule (various) · Samsonite (Sulfosalt) · Zincobotryogen (sulfate)

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