NWA 5549

North West Africa
Find, 2008

Iron, IAB-MG, silicated
Complite specimen, 1840g
Size: 10,5 x 11,0 x 7,0 cm

Remarks: Oriented individual

Petrography:
NWA 5549 is probably paired with the NWA 6369. The texture of NWA 6369 is similar to that of Horse Creek, classified as hexahedrite with unique lamellae of nickel silicide formed by breakdown of Si-rich metal along planes of widmanstätten structure. These two meteorites possible represent a new type of the FeNi-metal texture. We propose that minor elements like Si in the Horse Creek metal and C in the NWA 6369 metal led to formation of the unique texture unknown for other irons that consist mainly of Fe-Ni-P. Despite the textural similarity, a genetic relation between Horse Creek and NWA 6369 are not observed from siderophile elements.

Geochemistry:
Co (mg/g) 4.55, Ni (mg/g) 68.8, Ga (µg/g) 81.6, Ge (µg/g) 370, As (µg/g) 4.1, Ir (µg/g) 4.1, Au (µg/g) 1.49.

Submitter:
J. T. Wasson, UCLA.

Reference:
Meteoritical Bulletin Database
S. N. Teplyakova, C. A. Lorenz, M. A. Ivanova, A. V. Korochantsev, S. E. Borisovsky , I. A. Franchi and M. Humayun; Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow:The New Silicate-bearing Iron Meteorite NWA 6369 Paired to NWA 5549