NWA 5549

A COMPLETE SLICE OF A SILICATED IRON METEORITE

As a silicated iron meteorite, NWA 5549 features a large number of crystalline inclusions throughout the iron-nickel matrix of the meteorite. The matrix shows a course Widmanstätten pattern, larger and much more irregular than on most other iron meteorites, demonstrating that the metallic portion of this meteorite is relatively low in nickel and thus made up mostly of high-iron kamacite alloy.

Researchers believe that meteorites in the IAB group, including NWA 5549, were formed neither in the core of an asteroid like most iron meteorites, nor at the core-mantle boundary of an asteroid like most pallasites, but were instead created near the surface of an asteroid following an impact that produced superheated melt pools where iron and silicate constituents could separate from each other before recombining.

REFERENCES:

Meteoritical Bulletin Entry for NWA 5549