Hausmannite is a

complex oxide A complex oxide is a chemical compound that contains oxygen and at least two other elements (or oxygen and just one other element that's in at least two oxidation states). Complex oxide materials are notable for their wide range of magnetic and ...

, or a

mixed oxide In chemistry, a mixed oxide is a somewhat informal name for an oxide that contains cations of more than one chemical element or cations of a single element in several states of oxidation.Advanced Inorganic Chemistry, F. A. Cotton, G. Wilkinson ...

, of

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

containing both di- and tri-valent manganese. Its chemical formula can be represented as , or more simply noted as , or , as commonly done for

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...

(), the corresponding

iron oxide An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron ...

. It belongs to the

spinel group The spinels are any of a class of minerals of general formulation which crystallise in the cubic (isometric) crystal system, with the X anions (typically chalcogens, like oxygen and sulfur) arranged in a cubic close-packed lattice and the cations ...

and forms

tetragonal In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the Cube (geometry), cube becomes a rectangular Pri ...

crystals. Hausmannite is a brown to black metallic mineral with

Mohs hardness The Mohs scale ( ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fair ...

of 5.5 and a

specific gravity Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...

of 4.8. The type locality is Oehrenstock (Öhrenstock), Ilmenau, Thuringian Forest,

Thuringia, Germany Thuringia (; officially the Free State of Thuringia, ) is one of Germany's 16 states. With 2.1 million people, it is 12th-largest by population, and with 16,171 square kilometers, it is 11th-largest in area. Erfurt is the capital and lar ...

, where it was first described in 1813. Locations include

Batesville, Arkansas Batesville is the largest city in and the county seat of Independence County, Arkansas, United States, 80 miles (128 km) northeast of Little Rock, the state capital. According to the 2010 Census, the population of the city was 10,268. The c ...

, US; Ilfeld,

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

; Langban,

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

; and the

Ural Mountains The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. High quality samples have been found in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

where it is associated with other manganese oxides,

pyrolusite Pyrolusite is a mineral consisting essentially of manganese dioxide ( Mn O2) and is important as an ore of manganese.. It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure, sometimes forming reniform ...

and

psilomelane Psilomelane is a group name for hard black manganese oxides including hollandite and romanechite. Psilomelane consists of hydrous manganese oxide with variable amounts of barium and potassium. Psilomelane is erroneously, and uncommonly, known as ...

and the iron-manganese mineral

bixbyite Bixbyite is a manganese iron oxide mineral with chemical formula: . The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 – 6.5. It is a somewhat rare mineral ...

. Wilhelm Haidinger (1827) named it in honour of

Johann Friedrich Ludwig Hausmann Johann Friedrich Ludwig Hausmann (22 February 1782 – 26 December 1859) was a German mineralogist. Biography He was born in Hannover and educated in Göttingen, where he obtained a PhD. Two years after making a geological tour of Denmark, Norwa ...

(1782–1859), Professor of Mineralogy,

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, Germany.

Image gallery

File:Hausmannite-131901.jpg, Hausmannite from

Wessels mine The Wessels mine is a mine located in the west of South Africa in Northern Cape. Wessels represents one of the largest manganese reserve in South Africa having estimated reserves of 198.8 million tonnes of manganese ore grading 55% manganese meta ...

Kalahari The Kalahari Desert is a large semiarid sandy savanna in Southern Africa covering including much of Botswana as well as parts of Namibia and South Africa. It is not to be confused with the Angolan, Namibian, and South African Namib coastal d ...

manganese fields,

Northern Cape Province The Northern Cape ( ; ; ) is the largest and most sparsely populated province of South Africa. It was created in 1994 when the Cape Province was split up. Its capital is Kimberley. It includes the Kalahari Gemsbok National Park, part of the Kga ...

, South Africa File:Hausmannite structure.jpg, Crystal structure of hausmannite File:Hausmannite-120647.jpg, Cluster from

Hotazel Hotazel is a town in John Taolo Gaetsewe District Municipality in the Northern Cape province of South Africa. The town serves the manganese mines, 147 km (91 mi) north of Postmasburg and 46 km (28.6 mi) north-west of Kuruman ...

manganese fields,

Northern Cape The Northern Cape ( ; ; ) is the largest and most sparsely populated Provinces of South Africa, province of South Africa. It was created in 1994 when the Cape Province was split up. Its capital is Kimberley, South Africa, Kimberley. It includes ...

Province,

File:Ettringite-Hausmannite-Oyelite-Ettringite-Kalahari-Namibia-85mm 0623.jpg,

Ettringite Ettringite is a hydrous calcium aluminium sulfate mineral with formula: . It is a colorless to yellow mineral crystallizing in the trigonal crystal system, system. The prismatic crystals are typically colorless, turning white on partial dehydratio ...

crystal on a matrix of hausmannite and

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

, coated by oyelite

References

Manganese(II,III) minerals Spinel group Tetragonal minerals Minerals in space group 141 {{mineral-stub