Romanèchite

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title: "Romanèchite" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["barium-minerals", "manganese(iii,iv)-minerals", "oxide-minerals", "monoclinic-minerals", "minerals-in-space-group-12"] description: "Baryum manganese oxide mineral" topic_path: "general/barium-minerals" source: "https://en.wikipedia.org/wiki/Romanèchite" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Baryum manganese oxide mineral ::

::data[format=table title="Infobox mineral"]

Field	Value
name	Romanèchite
image	Romanechite.jpg
imagesize	260px
caption	Romanèchite, from the Marquette County, Michigan, US.
category	Oxide minerals
formula
IMAsymbol	Rmn
strunz	4.DK.10
system	Monoclinic
class	Prismatic (2/m)
(same H-M symbol)
symmetry	C2/m
mohs	6–6.5
luster	Submetallic
streak	Blue-black
references
::

| name = Romanèchite | boxwidth = | boxbgcolor = | image = Romanechite.jpg | imagesize = 260px | alt = | caption = Romanèchite, from the Marquette County, Michigan, US. | category = Oxide minerals | formula = | IMAsymbol = Rmn | molweight = | strunz = 4.DK.10 | dana = | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = C2/m | unit cell = | color = | colour = | habit = | twinning = | cleavage = | fracture = | tenacity = | mohs = 6–6.5 | luster = Submetallic | streak = Blue-black | diaphaneity = | gravity = | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references =

::figure[src="https://upload.wikimedia.org/wikipedia/commons/a/a2/Structure_Romanèchite.jpg" caption="Polyhedral representation of the 2 x 3 tunnel structure of romanèchite. The red atoms represent Ba and H₂O.Turner S and Post JE (1988) American Mineralogist 73: 1155–1161"] ::

Romanèchite () 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. 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.

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. It occurs also in ferromanganese nodules from Lake Baikal.

File:XRF_map_Romanèchite.png|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).

References

References

1. Warr, L.N.. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine.
2. [http://webmineral.com/data/Romanechite.shtml Romanechite], Webmineral.com
3. [http://www.mindat.org/min-3441.html Romanechite], Mindat.org
4. (1977). "Simon & Schuster's Guide to Rocks and Minerals.". Simon & Schuster.
5. Turner S and Post JE (1988) American Mineralogist 73: 1155–1161
6. (October 2015). "Romanechite-structured Na(0.31)MnO(1.9) nanofibers as high-performance cathode material for a sodium-ion battery". Chemical Communications.
7. (March 1999). "Manganese oxide minerals: crystal structures and economic and environmental significance". Proceedings of the National Academy of Sciences of the United States of America.
8. (2017-09-01). "New insight into the origin of manganese oxide ore deposits in the Appalachian Valley and Ridge of northeastern Tennessee and northern Virginia, USA". GSA Bulletin.
9. 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. {{doi. 10.1016/j.gca.2007.02.007

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::