Surfaces polished and etched with nitric acid reveal a system of lamellae which is called Widmanstatten structure. So far, it has not proved possible to produce such a system of lamellae experimentally. Gray black mixture of extremely small crystals of kamacite and taenite which fill in the spaces in the system of lamellae. Ataxite Finely crystalline, nickel-rich iron meteorite without a clearly defined structure. Probably derived from octahedrite because of the effects of heating.
Stony meteorites are similar to terrestrial rocks.
Their mineral content corresponds approximately to peridotites or gabbros. Small amounts of nickel-iron are also present. They are more abundant than iron meteorites. The groundmass consists of the same minerals or of glass. Color usually light to dark gray, sometimes black.