Hausmannite

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Hausmannite
Hausmannite-215565.jpg
General
CategoryOxide mineral
Formula
(repeating unit)
Mn2+Mn3+2O4
IMA symbolHsm[1]
Strunz classification4.BB.10
Crystal systemTetragonal
Crystal classDitetragonal dipyramidal (4/mmm)
H-M symbol: (4/m 2/m 2/m)
Space groupI41/amd
Unit cella = 5.76 Å
c = 9.46 Å; Z = 4
Identification
Formula mass228.81 g/mol
ColorBrownish black, grayish.
Crystal habitMassive - granular - common texture observed in granite and other igneous rock. pseudo octahedral - crystals show an octahedral outline.
TwinningRepeated twins on {112}
Cleavage[001] Perfect
FractureUneven - flat surfaces (not cleavage) fractured in an uneven pattern.
TenacityBrittle
Mohs scale hardness5.5
LusterSubmetallic
StreakDark reddish brown
DiaphaneityOpaque, transparent on thin edges
Specific gravity4.7 - 4.84, average = 4.76
Optical propertiesUniaxial (-)
Refractive indexnε = 2.15, nω = 2.46
Birefringenceδ = 0.31
Other characteristicsAnisotropism: Distinct, bireflectance: weak; O = light gray; E = dark gray.
References[2][3][4]

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, where it was first described in 1813.[3] Locations include Batesville, Arkansas, US; Ilfeld, Germany; Langban, Sweden; and the Ural Mountains, Russia.[2] High quality 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. Wilhelm Haidinger (1827) named it in honour of Johann Friedrich Ludwig Hausmann (1782–1859), Professor of Mineralogy, University of Göttingen, Germany.[3]

Image gallery[edit]

References[edit]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Hausmannite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 2 July 2022.
  3. ^ a b c Hausmannite, Mindat.org, retrieved 2 July 2022
  4. ^ Barthelmy, David (2014). "Hausmannite Mineral Data". Webmineral.com. Retrieved 2 July 2022.