Chemistry:Taenite
| Taenite | |
|---|---|
 Widmanstätten patterns of kamacite and taenite, from a meteorite currently in the Natural History Museum, London. | |
| General | |
| Category | Metals and intermetallic alloys |
| Formula (repeating unit) | γ-(Ni,Fe) |
| Strunz classification | 1.AE.10 |
| Crystal system | Isometric |
| Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) |
| Space group | Fm3m |
| Identification | |
| Color | metallic grayish to white |
| Cleavage | None |
| Fracture | Hackly fracture |
| Tenacity | Malleable, flexible |
| Mohs scale hardness | 5–5.5 |
| |re|er}} | metallic |
| Streak | light gray |
| Diaphaneity | Opaque |
| Specific gravity | 7.8–8.22 |
| Other characteristics | magnetic, not radioactive |
| References | [1][2] |
Taenite is a mineral found naturally on Earth mostly in iron meteorites. It is an alloy of iron and nickel, with a chemical formula of Fe,Ni and nickel proportions of 20% up to 65%.
The name is derived from the Greek ταινία for "band, ribbon". Taenite is a major constituent of iron meteorites. In octahedrites it is found in bands interleaving with kamacite forming Widmanstätten patterns, whereas in ataxites it is the dominant constituent. In octahedrites a fine intermixture with kamacite can occur, which is called plessite.
Taenite is one of four known Fe-Ni meteorite minerals: The others are kamacite, tetrataenite, and antitaenite.
Properties
It is opaque with a metallic grayish to white color. The structure is isometric-hexoctahedral (cubic). Its density is around 8 g/cm3 and hardness is 5 to 5.5 on the Mohs scale. Taenite is magnetic, in contrast to antitaenite. The structure is isometric-hexoctahedral (cubic). The crystal lattice has the c≈a=Template:Value.[4] The Strunz classification is I/A.08-20, while the Dana classification is 1.1.11.2.
Meteorite localities with taenite
- Campo del Cielo strewn field in Argentina .
- Henbury Meteorites Conservation Reserve in Australia .
- Canyon Diablo in Arizona.
See also
References
- ↑ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Taenite". Mineral Data Publishing. http://www.handbookofmineralogy.org/pdfs/taenite.pdf.
- ↑ http://webmineral.com/data/Taenite.shtml Webmineral data
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ Albertsen, F.; Knudsen, J. M.; Jensen, G. B. (Jun 1978). "Structure of taenite in two iron meteorites J.". Nature 273 (5662): 453–454. doi:10.1038/273453a0. Bibcode: 1978Natur.273..453A.
- Mason B., 1962: Meteorites. J. Wiley & Sons, New York [ISBN missing]
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