An extensive paper titled “Expertise and Analysis of a Sample of Ziz Meteorite” (EMTT, 2000) on the Ziz (NWA 854) iron meteorite was kindly provided by fellow meteoriticist Marcin Cimala from Poland. One of the inereresting results the EMTT presented is the fact that the spectrometric analysis determined an unusually hig ammount of germanium (640ppm) in NWA 854.
Considering our doubts concerning a pairing of Ziz (NWA 854) and the recently found material, we decided to submit a representative sample of the new material for classification under MetSoc requirements. The classification results published in Met. Bull. No. 98 show different values and the meteorite was declared a different find and received the NWA-number 6203. This is the classification result:
Petrography: (C. Herd and G. Nadeau, UAb) The meteorite contains abundant silicate inclusions. The metal consists of coarse-grained (~5 mm width) equigranular kamacite grains with 120° grain boundaries. Neumann lines are visible within individual kamacite grains. Small (sub-mm) schreibersite grains are present within some kamacite grains and at grain boundaries. Silicate inclusions consist of irregular, mm- to cm-scale masses of fine-grained (<0.2 mm) material intergrown with kamacite. Terrestrial oxides decorate grain boundaries and fractures that penetrate well within the meteorite interior.
Geochemistry: Mineral compositions (all mol%): Silicate inclusions consist of homogeneous olivine (Fa4.9±0.2), low-Ca pyroxene (Fs6.9±0.3Wo1.8±0.3), clinopyroxene (Fs3.0±0.1Wo44±1), and plagioclase (An15.7±0.1Ab81.2±0.1). Also associated with the silicate inclusions are abundant troilite, kamacite, schreibersite and graphite, the latter either fine-grained massive or cliftonitic (as intergrowths with troilite). Modal abundances in the one silicate inclusion studied in detail are approximately 30% olivine, 15% low-Ca pyroxene, 15% Ca pyroxene, 15% graphite, 10% troilite, 10% iron oxides (terrestrial), 3% kamacite, 2% plagioclase and trace schreibersite. Bulk Composition (metal): INAA data (J. Duke, UAb): Ni = 6.28 ± 0.04 wt%, Co = 0.441 ± 0.003 wt%, Ga = 81.2 ± 0.6 μg/g, Ge = 377 ± 34 μg/g, Ir = 3.55 ± 0.04 μg/g, Au = 1.51 ± 0.02 μg/g, As = 11.0 ± 0.2 μg/g, W = 0.72 ± 0.13 μg/g, Re = 0.33 ± 0.04 μg/g (uncertainties 1σ, 68% confidence level).
Classification: Iron meteorite, IAB main group, low shock, moderate weathering. Silicate inclusion mineralogy is consistent with IAB-MG. The lack of Widmanstätten pattern precludes structural classification.