Hello list, these two ungrouped irons have been approved 16 september on the MetSoc Database :
http://tin.er.usgs.gov/meteor/metbull.php?code=51756 http://tin.er.usgs.gov/meteor/metbull.php?code=51757 Both have unusual pattern when etched, both are mineralogicaly interesting : NWA 6166 : Iron meteorite, structurally anomalous plessitic octahedrite, ungrouped, very low weathering grade. The matrix surrounding the kamacite occurs in two different types: some zones have a very homogeneous (up to 0.1 mm scale) Ni-rich metal matrix; other zones are made of a rather coarse (10-50 µm) intergrowth of Ni-rich and Ni-poor metal arranged into irregular but continuous ribbons NWA 6167 : Iron meteorite (silicated), Ni-rich ataxite, ungrouped, very low weathering grade The studied 16.5 cm2 surface contains five rounded silicate inclusion (up to 6.8 mm in maximum length). They consist of prevailing crystals of olivine (Fo79.6±0.6), low-Ca pyroxene (En78-80 Wo2.2-3.1), high-Ca pyroxene (En49-51 Wo41-42), plagioclase (An78-85), Ca-phosphate and chromite. Close to the boundary with the Fe-Ni metal, the silicate crystals are crossed by tiny veinlets of very fine-grained Fe-Ni metal+troilite or iron oxyhydroxides. You can found here the last NWA 6166 I have, the main mass, and the last slice of NWA 6167 : http://wwmeteorites.com/NWA6166-6167.html The last specimen of NWA 6167, the 95g main mass is available uppon request. Fabien ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
