Romanèchite
| Romanèchite | |
|---|---|
| File:Romanechite.jpg Romanèchite, from the Marquette County, Michigan, US. | |
| General | |
| Category | Oxide minerals |
| Formula | (Ba,H2O)2(Mn4+,Mn3+)5O10 |
| IMA symbol | Rmn[1] |
| Strunz classification | 4.DK.10 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/m |
| Identification | |
| Mohs scale hardness | 6–6.5 |
| Luster | Submetallic |
| Streak | Blue-black |
| References | [2][3][4] |
Romanèchite ((Ba,H2O)2(Mn4+,Mn3+)5O10) is the primary constituent of psilomelane, which is a mixture of minerals. Most psilomelane is not pure romanechite, so it is incorrect to consider them synonyms. Romanèchite is a valuable ore of manganese, which is used in steelmaking and sodium battery production.[6] It has a monoclinic crystal structure, a hardness of 6 and a specific gravity of 4.7–5. Romanèchite's structure consists of 2 × 3 tunnels formed by MnO6 octahedra.[5][7]
It is commonly associated with hematite, barite, pyrolusite, quartz and other manganese oxide minerals. It has been found in France, Germany, England, Brazil, Russia, India, and various parts of the United States, including Arizona, Virginia, Tennessee and Michigan, and sites throughout the Appalachian Valley and Ridge.[8] It occurs also in ferromanganese nodules from Lake Baikal.[9]
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Bicolor (left) and tricolor (right) X-ray fluorescence maps of the distribution of Mn, Fe, and Ba in a ferromanganese nodule from Lake Baikal. Size = 5 mm (H) × 3 mm (V).[9]
![Bicolor (left) and tricolor (right) X-ray fluorescence maps of the distribution of Mn, Fe, and Ba in a ferromanganese nodule from Lake Baikal. Size = 5 mm (H) × 3 mm (V).[9]](/index.php/File:XRF_map_Roman%C3%A8chite.png){kind=link}
References
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- ^ Romanechite, Webmineral.com
- ^ Romanechite, Mindat.org
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Turner S and Post JE (1988) American Mineralogist 73: 1155–1161
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
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- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Manceau A, Kersten M, Marcus MA, Geoffroy N. and Granina L (2007) "Ba and Ni speciation in a nodule of binary Mn oxide phase composition from Lake Baikal". Geochimica et Cosmochimica Acta, 71: 1967–1981. Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).