Manganite
Species
Uncommon · Mn³⁺O(OH)
Manganese oxyhydroxide in dark steel grey prisms, deeply striated and grouped in bundles, with a reddish brown streak. It forms in low-temperature veins and hot-spring deposits and among other manganese oxides in clays and laterites; the veins of Ilfeld in the Harz gave the classic crystals. An ore of manganese with pyrolusite and the other oxides.
Identity
- Formula
- Mn³⁺O(OH)
- Chemical class
- Oxide
- Ore of
- Manganese
Crystallography
- Crystal system
- Monoclinic
- Habits
- Prismatic, Columnar, Fibrous, Granular, Massive
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 4
- Density
- 4.3 g/cm³
- Luster
- Submetallic
- Colors
- steel gray, iron-black
- Streak
- reddish brown to nearly black
- Transparency
- Opaque
Geology
- Origins
- Hydrothermal, Sedimentary
- Host rocks
- Granite, Volcanic rock, Sandstone, shale and clay
- Associated minerals
- Pyrolusite, Braunite, Barite, Calcite, Siderite, Goethite
- Found in
- Hydrothermal vein (lode), Lateritic deposit, Oxidized zone (gossan)
- Geography
- Germany (Ilfeld, Harz; Ilmenau, Thuringia), England (Botallack, Cornwall; Upton Pyne, Devon), Scotland (Granam, Aberdeenshire), USA (Negaunee, Michigan), South Africa (Kuruman)
Classification
- Rarity
- Uncommon
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Manganite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Manganite. Wikipedia.
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