Taenite

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Taenite
Widmanstatten patterns 2.jpg
General
Category Metals and intermetallic alloys
Formula
(repeating unit)
γ-(Ni,Fe)
Strunz classification 01.AE.10
Identification
Color metallic grayish to white
Crystal system isometric-hexoctahedral
Cleavage None
Fracture Hackly fracture
Tenacity Malleable, flexible
Mohs scale hardness 5-5.5
Luster metallic
Streak light gray
Diaphaneity Opaque
Specific gravity 7.8–8.22
Other characteristics magnetic, not radioactive
References [1][2]
Widmanstätten pattern showing the two forms of Nickel-Iron, Kamacite and Taenite, in an octahedrite meteorite

Taenite (Fe,Ni) is a mineral found naturally on Earth mostly in iron meteorites. It is an alloy of iron and nickel, with 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[edit]

It is opaque with a metallic grayish to white color. The structure is isometric-hexoctahedral. Its density is around 8 g/cm³ and hardness is 5 to 5.5 on the Mohs scale. Taenite is magnetic. The crystal lattice has the c≈a= 3.582ű0.002Å.[3] The Strunz classification is I/A.08-20, while the Dana classification is 1.1.11.2 . It is a Hexoctahedral (cubic) in structure.

Meteorite Localities with this Mineral[edit]

See also[edit]

References[edit]

  1. ^ http://rruff.geo.arizona.edu/doclib/hom/taenite.pdf Handbook of Mineralogy
  2. ^ http://webmineral.com/data/Taenite.shtml Webmineral data
  3. ^ Albertsen, F.; Knudsen, J. M.; Jensen, G. B. (Jun 1978). "Structure of taenite in two iron meteorites J.". Nature 273 (5662): 453–454. Bibcode:1978Natur.273..453A. doi:10.1038/273453a0. 
  • Mason B., 1962: Meteorites. J. Wiley & Sons, New York