Hausmannite

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Hausmannite
Hausmannit 1.jpg
General
Category Oxide minerals
Formula
(repeating unit)
Mn2+Mn3+2O4
Strunz classification 04.BB.10
Identification
Formula 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. Wilhelm Haidinger (1827) named it in honour of Johann Friedrich Ludwig Hausmann (1782–1859), professor of mineralogy, University of Göttingen, Germany.

External links[edit]

Crystal structure of hausmannite
Hausmannite from Wessels Mine, Kalahari manganese fields, Northern Cape Province, South Africa. Size: 5.8 x 4.3 x 3.5 cm.