Northwest Africa 8789 (NWA 8789)

(Northwest Africa)

Purchased: 2014 Jan

Classification: Enstatite chondrite (EH3)

History: Purchased by Fabien Kuntz in January 2014 from a dealer in Rissani, Morocco.

Petrography: (A. Irving and S. Kuehner, UWS) Small, well-formed chondrules are set in a red-brown matrix (~30 vol.%). Minerals are orthopyroxene, silica polymorph (with enstatite in chondrules), albite, intermediate plagioclase, altered kamacite, suessite, schreibersite, troilite, gypsum (as "mothy" grains, probably after primary oldhamite) and rare forsterite. No CAI were found.

Geochemistry: Olivine (Fa_0.2, N =1), orthopyroxene (Fs_0.2-15.2Wo_0.0-1.5, N = 18), metal (Si 3.1 wt.%, Ni 2.7 wt.%, Co 0.5 wt.%, N = 2), suessite (Ni 80.7 wt.%, Si 14.8 wt.%, Fe 4.1 wt.%, Co <0.1 wt.%).

Classification: Enstatite chondrite (EH3). The relatively high proportion of matrix and presence of accessory suessite are anomalous features.

Specimens: 17.52 g including one polished thin section at PSF; main mass with Kuntz.