Akaganeit
| Akaganeit | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1962-004 |
| chemical formula |
|
|
Mineral class (and possibly department) |
Oxides and hydroxides |
|
System no. to Strunz and to Dana |
4.DK.05 ( 8th edition : IV / F.06) 01/06/06/01 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | I 2 / m (No. 12, position 3) |
| Lattice parameters |
a = 10.60 Å ; b = 3.03 Å; c = 10.51 Å β = 90.2 ° |
| Formula units | Z = 1 |
| Physical Properties | |
| Mohs hardness | not defined |
| Density (g / cm 3 ) | calculated: 3.52 |
| Cleavage | not defined |
| Break ; Tenacity | not defined |
| colour | yellowish brown to rusty brown |
| Line color | yellowish brown |
| transparency | transparent to translucent |
| shine | Diamond to metallic shine, earthy |
Akaganeit is a rarely occurring mineral from the mineral class of " oxides and hydroxides ". It crystallizes in the monoclinic crystal system with the idealized composition β – Fe 3+ O (OH, Cl), so from a chemical point of view it is an iron (III) oxide hydroxide with iron in the β – Fe modification . The formula parts hydroxide ion and chlorine indicated in the round brackets can represent each other in the formula ( substitution , diadochy), but are always in the same proportion to the other components of the mineral.
Akaganeit only develops microscopic, spindle-shaped crystals up to about five micrometers in length with a diamond-like to metal-like sheen , which are often arranged in tufted mineral aggregates . In general, however, it is found in the form of fine-grained to massive aggregates and earthy-matt, powdery coatings. The crystals themselves are transparent to translucent, even if aggregate forms appear rather opaque. The color of the mineral varies between yellowish-brown and rust-brown, while its line color is always yellowish-brown.
Etymology and history
The mineral was first discovered by Dr. M. Nambu from Sendai University in the “Akagane” copper mine near Esashi in Iwate Prefecture on the Japanese island of Honshū and named after its type locality . It was described in detail in 1962 by AL Mackay.
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , Akaganeit belonged to the class of "oxides and hydroxides" and there to the department of "hydroxides and oxidic hydrates (water-containing oxides with a layer structure)", where he named the " Akaganeit Group "with the system no. IV / F.06 and the other members boehmite , diaspor , feitknechtite , feroxyhyte , goethite , groutite , lepidocrocite , manganite , sword mannite and tsumgallite .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns Akaganeit to the class of "oxides and hydroxides", but there in the department of "oxides with the molar ratio of metal: oxygen = 1: 2 and comparable “a. This is further subdivided according to the relative size of the cations involved and the crystal structure, so that the mineral can be classified according to its composition and structure in the sub-section “With large (± medium-sized) cations; Tunnel structures "can be found where, together with Coronadit , Henrymeyerit , Hollandit , Manjiroit , Mannardit , Priderit and Redledgeit, the" Hollandit group "with the system no. 4.DK.05 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Akaganeit to the class of "oxides and hydroxides" and there in the department of "hydroxides and hydroxide-containing oxides". Here he is the only member of the unnamed group 06.01.06 within the sub-section "Hydroxides and hydroxide-containing oxides with the formula: X 3+ O OH".
Crystal structure
Akaganeit crystallizes monoclinically in the space group I 2 / m (space group no. 12, position 3) with the lattice parameters a = 10.60 Å ; b = 3.03 Å; c = 10.51 Å and β = 90.2 ° and one formula unit per unit cell .
Education and Locations
Akaganeite formed by weathering of pyrrhotite in the oxidation zone of limonite - deposits and is an important part in some soils and geothermal brines . Akaganeit can also arise in ore nodules in the sea floor and as a corrosion product in some meteorites. In addition to pyrrhotite, hibbingite can also occur as an accompanying mineral.
As a rare mineral formation, Akaganeit could only be detected at a few sites, whereby so far (as of 2013) around 50 sites are known. Its type locality, the “Akagane” copper mine, is the only known site in Japan to date.
In Germany, the mineral is known so far only from the Clara mine near Oberwolfach in Baden-Württemberg, the slag heaps of the Ochsenhütte and Herzog-Julius-Hütte in the Lower Saxony district of Goslar , Genna Zinkhütte near Letmathe in North Rhine-Westphalia and the shaft 366 of the Schneeberg deposit / Schlema / Alberoda in Saxony.
Akaganeit was also discovered in the “Campo del Cielo” meteorite in Argentina, near São Francisco do Sul in the Brazilian state of Santa Catarina , “Santa Catarina meteorite”, in the Nantan meteorite in the Chinese autonomous region of Guangxi, in the Dronino meteorite in Russia , found in the Muonionalusta meteorite in the Swedish municipality of Pajala .
Other well-known sites include Visé- Richelle in Belgium, the “Strathcona Mine” near Levack in the Canadian province of Ontario , the ancient slag heaps near Lavrio in the Greek region of Attica , the slag heaps near Campiglia Marittima and Piombino in Italy, the mine “Las Ánimas ”near La Mur in the municipality of Trincheras in Mexico, on White Island (Bay of Plenty) in New Zealand, the Kaskasnjuntschorr in the Chibinen on the Russian Kola peninsula and the Aldan highlands in Siberia, Zlatá Baňa in Slovakia, the“ Kerchenskoe ”iron ore deposit “Near Kerch on the Crimean peninsula in the Ukraine, the“ Gravel Hill Mine ”near St Agnes (Cornwall) in the United Kingdom and several locations in various states of the USA.
Akaganeit could also be detected in rock samples from the Mid-Atlantic Ridge and the Red Sea (deep drilling Atlantis II) as well as outside the earth from the moon in the rock samples brought from the Apollo 16 and Luna 24 missions.
See also
literature
- AL Mackay: β-ferric ohyhydroxide - akaganéite . In: Mineralogical Magazine . tape 33 , 1962, pp. 270–280 (English, rruff.info [PDF; 1.5 MB ; accessed on December 26, 2018]).
- Lawrence A. Taylor, Ho-Kwang Mao, PM Bell: Identification of the Hydrated Iron Oxide Mineral Akaganéite in Apollo 16 Lunar Rocks . In: Geological Society of America . tape 2 , no. 9 , 1974, p. 429-432 , doi : 10.1130 / 0091-7613 (1974) 2 <429: IOTHIO> 2.0.CO; 2 (English).
- Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 425 .
Web links
- Mineral Atlas: Akaganeit (Wiki)
- Akaganeite. In: mindat.org. Hudson Institute of Mineralogy, accessed December 26, 2018 .
- David Barthelmy: Akaganeite Mineral Data. In: webmineral.com. Accessed December 26, 2018 .
- American-Mineralogist-Crystal-Structure-Database - Akaganeite. In: rruff.geo.arizona.edu. Retrieved December 26, 2018 .
Individual evidence
- ↑ a b c d Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 226 (English).
- ↑ a b c Akaganeite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 70 kB ; accessed on December 26, 2018]).
- ^ IMA / CNMNC List of Mineral Names; February 2013 (PDF 1.3 MB)
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
- ↑ Geographical Names - Akagane Copper Mine: Japan. In: geographic.org. February 5, 1994, accessed December 26, 2018 .
- ↑ Mindat - Number of localities for Akaganeit
- ^ Frank S. Simons, Eduardo Mapes V .: Geology and ore deposits, Zimapan mining district, Hidalgo, Mexico. Las Animas mine . In: Geological Survey Professional Paper, Geological Survey (US) 284 . US Government Printing Office, Washington 1971, p. 94 ( limited preview in Google Book search).
- ↑ a b List of localities for Akaganeit at the Mineralienatlas and at Mindat