Rocks from Space Picture of the Day August 14, 2008
Like many other meteorites from Northwest Africa this particular iron has a misty find history. In spring and summer 2008 several Moroccan meteorite dealers started to offer individuals of a new meteoritic iron. While two dealers could not provide any background information another seller at the Ensisheim/France meteorite fair in June 2008 gave Ziz / Algeria as the find location of the newly recovered masses. To his knowledge the irons represented new finds of the well known Ziz IAB complex meteorite (NWA 854). Although this may indeed be the case the new finds display features that cast some doubt on a probable pairing. In particular Ziz is not known for centimeter sized silicate inclusions which make up ~40 volume percent of the new finds. Considering this uncertainty we decided to submit a representative sample of the new material for classification. The meteorite is currently scheduled for cutting. Any additional information readers may be able to contribute is appreciated.
Exterior morphology: The 1.873g mass has the shape of an irregular triaxial ellipsoid. Iron and silicate portions are distributed in a patchwork pattern on the meteorite´s exterior with a slight preponderance of the metal proportions. Moderately eroded regmaglypts are visible on all surfaces with exception of the silicate portions. The texture of the iron surfaces is alternating from undulating surfaces smoothened by atmospherical ablation to a coarser pattern where corrasion (sand abrasion) has eroded up to ~1 mm of the original material. Iron surface areas which were in situ protected from corrasion developed a chestnut colored desert patina. The latter has preserved remains of the fusion rind coating on the bottom of single depressions. Iron surfaces altered through corrasion show a matt-finished slightly olive luster in which the lamellae boundaries are apparent. The boundaries of iron and silicate portions are exaggerated through chemical and mechanical weathering. Obviously the silicate portions have lost a higher amount of surface material in this process. The silicate portion is fine grained and of inhomogeneous composition. Olivine crystals reaching 2mm in diameter are visible with the unaided eye. Click here for more images.
© Dr. Svend Buhl www.meteorite-recon.com
Author & editor
Michael Johnson
