Ataxite

Ataxite
— Structural class —
The Chinga meteorite is an ataxite.
GroupIVB or "Iron, ungrouped", occasionally IAB or others
CompositionMainly Meteoric iron, nickel (>18%), no Widmanstätten patterns
A phase diagram showing the link between structural and chemical classification.
The Santiago Papasquiero meteorite, an ataxite found in 1958 in Durango, Mexico. It consists of a finely crystalline mix of kamacite & taenite, plus other minor minerals. Santiago Papasquiero is a strange ataxite that appears to be a completely metamorphosed and recrystallized octahedrite. Field of view ~2.5 cm across. This is a cut, polished, nitric acid-etched surface.

Ataxites (from Greek meaning "without structure") are a structural class of iron meteorites with a high nickel content and show no Widmanstätten patterns upon etching.