Octahedrites are the most common structural class of iron meteorites. The structures occur because the meteoric iron has a certain nickel concentration that leads to the exsolution of kamacite out of taenite while cooling. Octahedrites derive their name from the crystal structure paralleling an octahedron.

An iron with very narrow bands, less than 1mm, (example: the Gibeon iron from Namibia) is described as a fine octahedrite. At the other end of the scale is the coarsest octahedrite (example: Sikhote-Alin from Russia ) that may display a bandwidth of 3 cm or more.

Iron meteorites are thought to be samples of metallic cores and pools that formed in diverse small planetary bodies. Their great diversity offers remarkable insights into the formation of asteroids and the early history of the solar system.

Octahedrites contain both kamacite and taenite and constitute the largest group of iron finds. Most ataxites, which are the rarest group, are pure taenite; some ataxite specimens contain up to 69 percent nickel.

Octahedrite is a historical classification for iron meteorites based on structure. It shows a Widmanstätten pattern of kamacite exsolution lamellae out of taenite. See also octahedrite (of Werner), a synonym of anatase.

Most Common type of iron meteorite, composed mainly of taenite and kamacite and named for the octahedral (eight-sided) shape of the kamacite crystals. When sliced, polished and etched with an acid such as nitric acid, they display a characteristic Widmanstätten pattern.

Octahedrite is the most common type of Fe-Ni meteorite that falls to Earth. Other Fe-Ni meteorite rock types include hexahedrite and ataxite. The rock names octahedrite-hexahedrite-ataxite reflect an iron meteorite classification based on the physical crystalline structure of the iron-nickel minerals present.

: an iron meteorite having plates of kamacite with narrow selvages of taenite and interstitial plessite constituting a very intimate mixture of kamacite and taenite compare widmannstaetten figures. French octaédrite, from octaèdre octahedron (from Greek oktaedron) + -ite.

An obsolete synonym for anatase, one of the three known titanium dioxide minerals, is also called octahedrite. Octahedrites are the most common structural class of iron meteorites, formed by cooling meteoric iron with a specific nickel concentration leading …

Octahedrites are the most common structural class of iron meteorites. The structures occur because the meteoric iron has a certain nickel concentration that leads to the exsolution of kamacite out of taenite while cooling. Quick Facts Compositional type ... A phase diagram showing the link between structural and chemical classification.