WordNet
- a mineral consisting of hydrated basic oxide of manganese and barium; a source of manganese
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出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/09/05 22:04:18」(JST)
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Psilomelane |
A native sample of psilomelane
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General |
Category |
Manganese oxides |
Formula
(repeating unit) |
The general formula
Ba(Mn2+)(Mn4+)8O16(OH)4 or as (Ba,H2O)2Mn5O10
Barium Manganese Oxide Hydroxide |
Identification |
Formula mass |
590.03 gm |
Color |
black with gray pyrolusite bands |
Crystal habit |
Botryoidal, Mammillary, Reniform |
Crystal system |
monoclinic |
Cleavage |
none |
Fracture |
conchoidal and uneven |
Mohs scale hardness |
5.0 - 6.0 |
Luster |
Sub-Metallic, Dull |
Streak |
brownish black |
Diaphaneity |
Opaque |
Specific gravity |
3.7 - 4.7 |
Polish luster |
vitreous to subadamantine |
Solubility |
in hydrochloric acid |
Other characteristics |
hard black manganese oxides such as hollandite and romanechite |
Psilomelane, erroneously, and uncommonly known as black hematite (but not related to true hematite, which is an iron ore), is a group name for hard black manganese oxides such as hollandite and romanechite. Psilomelane consists of hydrous manganese oxide with variable amounts of barium and potassium.
Contents
- 1 Formula
- 2 Characteristics
- 3 History and occurrence
- 4 See also
- 5 References
Formula
Generalized formula may be represented as Ba(Mn2+)(Mn4+)8O16(OH)4 or as (Ba,H2O)2Mn5O10. It is sometimes considered to be a hydrous manganese manganate, but of doubtful composition. The amount of manganese present corresponds to 70-80% of manganous oxide with 10-15% of available oxygen.
Characteristics
Psilomelane is amorphous and occurs as botryoidal and stalactitic masses with a smooth shining surface and submetallic lustre. The mineral is readily distinguished from other hydrous manganese oxides (manganite and wad) by its greater hardness 5 to 6; the specific gravity varies from 3.7 to 4.7. The streak is brownish black and the fracture smooth. Owing to its amorphous nature, the mineral often contains admixed impurities, such as iron hydroxides. It is soluble in hydrochloric acid with evolution of chlorine gas.
History and occurrence
Dendritic psilomelane on a cobble
The name has reference to this characteristic appearance, from the Greek for (naked, smooth) and (black); a Latinized form is calvonigrite, and a German name with the same meaning is Schwarzer Glaskopf.
It is a common and important ore of manganese, occurring under the same conditions and having the same commercial applications as pyrolusite. It is found at many localities; amongst those which have yielded typical botryoidal specimens may be mentioned the Restormel iron mine at Lostwithiel in Cornwall, Brendon Hills in Somerset, Hoy in Orkney, Sayn near Coblenz, and Crimora in Augusta county, Virginia. With pyrolusite it is extensively mined in Vermont, Virginia, Arkansas, and Nova Scotia.
Polished specimen of manganese ore from the Batesville, Arkansas district. Slab of manganese ore showing an intimate mixture of hausmannite and psilomelane in a roughly zonal arrangement and a radiating mass of white barite at the center. The light steel-gray mineral and the black mineral immediately adjacent to the barite are
psilomelane. The rest of the black mineral is
hausmannite. Natural size.
See also
Other manganese oxides:
References
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.
- Mindat with locality data
- Webmineral
- Mineral galleries
Manganese minerals
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Borates |
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Carbonates |
- Ankerite
- Kutnohorite
- Rhodochrosite
- Manganoan Calcite
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Oxides |
Simple
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- Hausmannite
- Manganite
- Manganosite
- Nsutite
- Pyrolusite
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Mixed
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- Birnessite
- Bixbyite
- Ferrocolumbite
- Ferrotantalite
- Galaxite
- Jacobsite
- Manganotantalite
- Psilomelane
- Romanèchite
- Tantalite
- Todorokite
- Umber
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Phosphates |
- Childrenite
- Graftonite
- Lithiophilite
- Natrophilite
- Purpurite
- Triplite
- Triploidite
- Zanazziite
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Silicates |
- Babingtonite
- Bixbite
- Braunite
- Brownleeite
- Calderite
- Chloritoid
- Eudialyte
- Glaucochroite
- Jeffersonite
- Knebelite
- Ottrelite
- Piemontite
- Pyroxferroite
- Rhodonite
- Spessartine
- Sugilite
- Tephroite
- Zakharovite
- Zircophyllite
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Sulfides |
- Alabandite
- Hauerite
- Rambergite
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Other |
- Axinite (borosilicate)
- Geigerite (arsenate)
- Manganese nodule (various)
- Samsonite (Sulfosalt)
- Zincobotryogen (sulfate)
- Wolframite
- Hübnerite
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English Journal
- [Bacterial leaching of manganese ores].
- Belyĭ AV, Pustoshilov PP, Gurevich IuL, Kadochnikova GG, Ladygina VP.
- Prikladnaia biokhimiia i mikrobiologiia.Prikl Biokhim Mikrobiol.2006 May-Jun;42(3):327-31.
- Leaching of various types of ores, containing 12-30% manganese, by the thiobacterium Acidithiobacillus ferrooxidans was studied. Leaching of reduced ores (manganocalcite and manganiferous limestone) was mediated mainly by degradation of manganiferous minerals (by sulfuric acid produced in the course
- PMID 16878550
Japanese Journal
- Natural cryptomelane and its potential application in the adsorption of heavy metal cadmium
- Journal of mineralogical and petrological sciences 102(4), 217-225, 2007-08-01
- NAID 10019151192
- Mineralogy and genesis of Kutinga manganese deposit, South Orissa, India.
- エジプト・セントラルイースタン砂漠の北部カリエム涸川におけるアルカリ岩中のウラン鉱化作用
Related Links
- General Psilomelane Information Chemical Formula: (Ba,H2O)2Mn5O10 Composition: Molecular Weight = 590.03 gm Barium 23.27 % Ba 25.99 % BaO Manganese 46.56 % Mn 66.89 % Mn 2 O 3 Hydrogen 0.34 % H 3.05 % H ...
- Obsolete group name for hard black <m>Manganese Oxides</m> ... No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.