hexahedrite

…groups grading into one another: hexahedrites, octahedrites, and ataxites. Hexahedrites are usually made up entirely of kamacite and lack the Widmanstätten pattern. 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…

…is the class known as hexahedrites, which are composed almost entirely of kamacite. Being nearly of a single mineral, hexahedrites are essentially structureless except for shock features. At the other extreme is the class known as ataxites, which are made up primarily of taenite. Ataxites are the rarest class and…

…comprises all the metal in hexahedrites; it also is a principal constituent of the octahedrites, where it is intergrown with taenite, a face-centred cubic nickel-iron mineral.