Back منغنيت Arabic Manganita AST Manqanit AZ Манганіт BE Manganit BS Manganita Catalan Manganit Czech Manganit German Μαγγανίτης Greek Manganito EO
| Manganite | |
|---|---|
 | |
| General | |
| Category | Oxide mineral |
| Formula (repeating unit) | MnO(OH) |
| IMA symbol | Mnn[1] |
| Strunz classification | 4.FD.15 |
| Dana classification | 06.01.03.01 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/c |
| Unit cell | a = 5.3 Å, b = 5.278 Å, c = 5.307 Å; β = 114.36°; Z = 4 |
| Identification | |
| Color | Dark steel-gray to black, reddish brown in transmitted light, gray-white with brownish tint, with blood-red internal reflections in reflected light |
| Crystal habit | Slender prismatic crystals, massive to fibrous, pseudo-orthorhombic |
| Twinning | {011} |
| Cleavage | {010} perfect, {110} and {001} good |
| Fracture | Uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 4 |
| Luster | Sub-metallic |
| Streak | Reddish brown to nearly black |
| Diaphaneity | Opaque, transparent on thin edges |
| Specific gravity | 4.29–4.34 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 2.250(2) nβ = 2.250(2) nγ = 2.530(2) |
| Birefringence | δ = 0.280, Bireflectance: distinct in grays |
| Pleochroism | Faint |
| 2V angle | Small |
| Dispersion | Very strong |
| References | [2][3][4][5][6][7] |
Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic).[3] Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles. The color is dark steel-grey to iron-black, and the luster brilliant and submetallic. The streak is dark reddish brown. The hardness is 4, and the specific gravity is 4.3. There is a perfect cleavage parallel to the brachypinacoid, and less-perfect cleavage parallel to the prism faces. Twinned crystals are not infrequent.
The mineral contains 89.7% manganese sesquioxide; it dissolves in hydrochloric acid with evolution of chlorine.
- ^ 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.
- ^ Mineralienatlas
- ^ a b Handbook of Mineralogy
- ^ Mindat
- ^ Webmineral data
- ^ Klein, Cornelis and Cornelius S. Hurbut, Jr., Manual of Mineralogy, Wiley, 20th ed., 1985, p. 317 ISBN 0-471-80580-7
- ^ T. P. Moore, Famous Mineral Localities: Ilfeld, Harz Mountains, Thuringia, Germany, The Mineralogical Record, vol. 41, no. 6, 2010.