This image shows the
Widmanstätten pattern of a polished and etched slice of the Gibeon IVA
fine octahedrite. The light kamacite bands
are bordered by darker taenite ribbons. For
a more detailed image you can view a 100X photomicrograph (47K GIF) of a different Gibeon
specimen.
The angles formed by the bands
and ribbons are reflective of the angle of the slice cut to the octahedral
crystal structure of the nickel-iron -- two four-sided pyramids with bases
together. This slice, with angles close to 60° and 120°, was cut almost
parallel to a triangular face of the crystal. Had the cut been made
perpendicular to the vertical axis of the crystal the angles would have been
90°.
