Libertine
Libertine | |
---|---|
Black desert crust on the surface of a meteorite particle from the Sikhote-Alin meteorite (field of view approx. 4 mm × 3 mm) | |
General and classification | |
chemical formula | Fe 2+ O |
Mineral class (and possibly department) |
Oxides and hydroxides |
System no. to Strunz and to Dana |
4.AB.25 ( 8th edition : IV / A.04) 02/04/01/06 |
Crystallographic Data | |
Crystal system | cubic |
Crystal class ; symbol | cubic hexakisoctahedral; 4 / m 3 2 / m |
Space group | Fm 3 m (No. 225) |
Lattice parameters | a = 4.31 Å |
Formula units | Z = 4 |
Physical Properties | |
Mohs hardness | 5 |
Density (g / cm 3 ) | measured: 5.88; calculated: 5.97 |
Cleavage | no |
colour | black, brown, gray |
Line color | black |
transparency | opaque |
shine | Metallic luster |
magnetism | strong magnetic |
Wustite , also known under the chemical name iron (II) oxide , is a rarely occurring mineral from the mineral class of " oxides and hydroxides ". It crystallizes in the cubic crystal system with the chemical composition FeO and mainly develops crusts, intergranular fillings and massive aggregates that have a metallic sheen .
Wüstite is opaque in every form. Its color varies between brown and black in daylight, but it appears gray in incident light.
Etymology and history
Wüstit was named in 1927 after the German iron and steel scientist and founding director of the Kaiser Wilhelm Institute for Iron Research Fritz Wüst (1860–1938).
The mineral was first scientifically described in 1927 by Rudolf Schenck and Th. Dingmann. The type locality is Scharnhausen in Baden-Württemberg.
classification
Already in the outdated 8th edition of the mineral classification according to Strunz , the wüstite belonged to the mineral class of "oxides and hydroxides" and there to the department of "compounds with M 2 O and MO", where it together with bunsenite , calcium oxide , manganosite , monteponite and periclase the "Periclas series" with the system no. IV / A.04 .
In the last revised and updated Lapis mineral directory by Stefan Weiß in 2018 , which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. IV / A.04-20 . In the "Lapis system" this also corresponds to the department "Oxides with the ratio metal: oxygen = 1: 1 and 2: 1 (M 2 O and MO)", where wüstite together with bunsenite, calcium oxide, manganosite, monteponite, Murdochite , palladinite and periclase form the "periclase group".
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also classifies wüstite in the category of "oxides with the molar ratio of metal: oxygen = 2: 1 and 1: 1" . However, this is further subdivided according to the exact ratio between cations and anions as well as the relative size of the cations, so that the mineral is classified according to its composition in the sub-section "Cation: Anion (M: O) = 1: 1 (and up to 1: 1, 25); with only small to medium-sized cations "can be found, where together with bunsenite, calcium oxide, manganosite, monteponite and periclase as well as ferropericlase with previously questionable mineral status, the" periclase group "with the system no. 4.AB.25 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , also assigns the wüstite to the class of "oxides and hydroxides" and there into the "oxides" category. Here, too, it is together with periclase, bunsenite, manganosite, Monteponit, calcium oxide and Hongquiit in the "Periklasgruppe (isometric, Fm 3 m )" with the system number. 04.02.01 to be found in the subsection “ Simple oxides with a cation charge of 2+ (AO) ”.
Crystal structure
Wüstite crystallizes cubically under normal conditions in the space group Fm 3 m (space group no. 225) with the lattice parameter a = 4.31 Å and 4 formula units per unit cell . This crystal structure is also known as the NaCl or B1 structure.
In contrast to its extremely stable Mg-containing analog periclase (MgO), Wustite undergoes phase transformations even at pressures such as those in the earth's mantle. From around 17 GPa and temperatures of around 300 K, the transition from the NaCl structure (B1) to a rhombohedral crystal lattice occurs. The transition to a NiAs structure (B8) takes place at temperatures of around 600 K and more than 90 GPa. The lower the temperature, the wider the pressure interval in which the rhombohedral shape is stable.
Modifications and varieties
Magnesiowustite , (Fe, Mg) O, is a magnesium-containing variety of desertite.
Education and Locations
Magnesiowustite is one of two main components of the lower earth's mantle , but forms on the earth's surface primarily as a conversion product of other iron-containing minerals at high temperatures in a strongly reducing environment such as in strongly reduced, iron-containing basalts . It is found in the form of inclusions in diamonds , as a deposition product from deep sea springs ( black smokers ) and as Fe-Mn microspherolites in various geological environments and in some meteorites . As Begleitminerale occur among other akaganeite dignified, iron , goethite , hematite , ilmenite , lepidocrocite , magnetite , maghemite , pyrite , pyrrhotite and Troilite on.
In the earth's crust , wüstite is a rare natural mineral formation and has only been found in a few places, although around 80 sites have been documented so far (as of 2019). In addition to its type locality in Scharnhausen , the mineral was also found in Germany in the alluvial soil of the Frohnbach near Oberwolfach in Baden-Württemberg, in the slag of the Eisenhüttenkombinates Ost (EKO) near Eisenhüttenstadt in Brandenburg, near Bühl near Kassel in Hesse, in the Hölltal near Lautenthal in Lower Saxony, in the zinc smelter Genna in Iserlohn-Letmathe in North Rhine-Westphalia and on the Kammberg near Joldelund in Schleswig-Holstein.
Other sites are in Australia, Azerbaijan, China, France, Namibia, Oman, Poland, Romania, Russia, South Africa, the Czech Republic, the United States of America (USA) and outside of the earth in the moon rocks .
use
Wüstite is an important link in the reduction of iron ores and is mainly formed during the smelting process in the blast furnace from the magnetite previously formed. The equilibrium reaction between wüstite and magnetite is as follows:
It is also known as the weathering product of iron and steel slag or in the hot processing or heat treatment of ferrous metals ( mill scale ).
See also
literature
- Rudolf Schenck, Th. Dingmann: Equilibrium studies on the reduction, oxidation and carbonization processes in iron III . In: Journal of Inorganic and General Chemistry . tape 166 , 1927, pp. 141 , doi : 10.1002 / zaac.19271660111 ( rruff.info [PDF; 2,3 MB ; accessed on November 11, 2019]).
- KC Chandy: Short communications: An occurrence of wüstite . In: Mineralogical Magazine . tape 35 , 1965, pp. 664–666 (English, rruff.info [PDF; 121 kB ; accessed on November 11, 2019]).
- Martin Okrusch, Siegfried Matthes: Mineralogy. An introduction to special mineralogy, petrology and geology . 7th, completely revised and updated edition. Springer, Berlin [a. a.] 2005, ISBN 3-540-23812-3 , pp. 371 ff .
Web links
- Mineral Atlas: Wüstit (Wiki)
- Desolate. In: mindat.org. Hudson Institute of Mineralogy, accessed November 11, 2019 .
- David Barthelmy: Wüstite Mineral Data. In: webmineral.com. Retrieved November 11, 2019 .
Individual evidence
- ^ A b c Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 184 .
- ↑ Wüstite . 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; 71 kB ; accessed on November 11, 2019]).
- ↑ Rudolf Schenck, Th. Dingmann: Equilibrium investigations on the reduction, oxidation and carbonization processes in iron III . In: Journal of Inorganic and General Chemistry . tape 166 , 1927, pp. 141 , doi : 10.1002 / zaac.19271660111 ( rruff.info [PDF; 2,3 MB ; accessed on November 11, 2019]).
- ↑ 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 .
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed November 11, 2019 .
- ↑ Ho-kwang Mao, Jinfu Shu, Yingwei Fei, Jingzhu Hu, Russell J. Hemley: The wüstite enigma . In: Physics of the Earth and Planetary Interiors . tape 96 , no. 2-3 , 1996, pp. 135-145 , doi : 10.1016 / 0031-9201 (96) 03146-9 (English, researchgate.net [accessed November 11, 2019]).
- ↑ Localities for Wüstite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 11, 2019 .
- ↑ List of localities for the Mineralienatlas and Mindat , accessed on November 11, 2019.
- ^ Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 348-351 .