Octahedrite

The Oktaedrite are the most common group of nickel-iron meteorites. They consist of the minerals kamacite and taenite. When polished and etched the surface of this meteorite, the typical structures Widmanstättenschen show. They consist of kamacite - beams, which are separated by thin lamellae of taenite. In the third dimension of the plate is present in kamacite disposed parallel to the surfaces of an octahedron, hence the name octahedrite.

The Oktaedrite be further subdivided according to the width of the kamacite bars in structural classes ( there is a link with the nickel content):

• Worst Oktaedrite, more than 3.3 mm, 5-9 % Ni
• Rough Oktaedrite 1.3 to 3.3 mm, 6.5-8.5 % Ni
• Mean Oktaedrite, 0.5 to 1.3 mm, 7-13 % Ni
• Fine Oktaedrite, 0.2 to 0.5 mm, from 7.5 to 13 % of Ni
• Oktaedrite fine, less than 0.2 mm, 17-18% Ni

They can also be classified into the chemical groups I to IV depending on the content of the trace elements nickel and germanium, gallium, and iridium. In addition there are a number of octaedrite that so far none of these groups could be assigned and are therefore referred to as anomalous.

Known representatives of the Gibeon meteorite are Oktaedritgruppe, Sikhote -Alin meteorite, Campo del Cielo meteorite, Canon Diablo meteorite, meteorite Morasko, Nantan meteorite, of Toluca and the Cranbourne meteorite.