Akaganeite, also written as the deprecated Akaganéite,Ernst A.J. Burke (2008):
Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical marks
. ''Mineralogical Record'', volume 39, issue 2. is a

chloride The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). The pr ...

-containing

iron(III) oxide-hydroxide Iron(III) oxide-hydroxide or ferric oxyhydroxideA. L. Mackay (1960): "β-Ferric Oxyhydroxide". ''Mineralogical Magazine'' (''Journal of the Mineralogical Society''), volume 32, issue 250, pages 545-557. is the chemical compound of iron, oxygen, ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

, formed by the weathering of

pyrrhotite Pyrrhotite (''Pyrrhus of Epirus, pyrrhos'' in Greek language, Greek meaning "flame-coloured"'')'' is an iron sulfide mineral with the formula Fe(1−x)S (x = 0 to 0.125). It is a nonstoichiometric compound, nonstoichiometric variant of FeS, th ...

(Fe_1−''x''S). Akaganeite is often described as the β phase of

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

ferric oxyhydroxide , but some

(or

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an Inorganic chemistry, inorganic, Monatomic ion, monatomic Ion#Anions and cations, anion of fluorine, with the chemical formula (also written ), whose ...

) ions are normally included in the structure,Jongsik Kim and Clare P. Grey (2010), "Li Solid-State MAS NMR Study of Local Environments and Lithium Adsorption on the Iron(III) Oxyhydroxide, Akaganeite (β-FeOOH)". ''Chemistry of Materials'', volume 22, pages 5453–5462. so a more accurate formula is .C. Rémazeilles and Ph. Refait (2007):
On the formation of β-FeOOH (akaganéite) in chloride-containing environments
. ''Corrosion Science'', volume 49, issue 2, pages 844-857.

Nickel Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slo ...

may substitute for iron, yielding the more general formula Mineral 314-687: Akaganeite
. ''Mindat.org'' database, accessed on 2019-02-12. Akaganeite has a

metal A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...

lic luster and a brownish yellow streak. Its

crystal structure In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

and similar to that of hollandite , characterised by the presence of tunnels parallel to the c-axis of the tetragonal lattice. These tunnels are partially occupied by chloride anions that give to the crystal its structural stability.

Occurrence

The mineral was discovered in the Akagane mine in Iwate,

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, for which it is named. It was described by the Japanese mineralogist Matsuo Nambu in 1968, but named as early as 1961. Alan Lindsay Mackay (1962): "β-ferric oxyhydroxide - akaganéite", in ''Mineralogical Magazine and Journal of the Mineralogical Society'', volume 33, issue 259, pages 270-280. Cites a private communication by Matsuo Nambu (1961). Note: the diacritic in the title is incorrect, see Burke (2008). Reviewed by Mandarino (1963) in ''American Minralogist''J. A. Mandarino (1963):
New Mineral Names: Akaganéite
. ''American Mineralogist'', volume 48, issues 5-6, page 711. Short review of Mackay's communication (1962) in ''Mineralogical Magazine''. Note: the diacritic in the title is incorrect. Akaganeite has also been found in widely dispersed locations around the world and in rocks from the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

that were brought back during the Apollo Project. The occurrences in

meteorite A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...

s and the lunar sample are thought to have been produced by interaction with

Earth's atmosphere The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weathe ...

. It has been detected on Mars through orbital imaging spectroscopy.

References

External links

Mindat with locationsWebmineral
Iron(III) minerals Chloride minerals Oxide minerals Monoclinic minerals Minerals in space group 12 Minerals described in 1968 {{Oxide-mineral-stub

Occurrence

See also

References

External links