Kaliwoda, Melanie; Hochleitner, Rupert; Hoffmann, Viktor H.; Mikouchi, Takashi; Gigler, Alexander M.; Schmahl, Wolfgang W.
New Raman Spectroscopic Data of the Almahata Sitta Meteorite.
In: Spectroscopy Letters, Vol. 46, No. 2: pp. 141-146
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Raman spectroscopy is a convenient method to classify polytypes pluspolymorphs and to investigate different compositions, structures, andmodifications of minerals. This information is required to classifymeteorites of different mineral compositions. Our intention was toexamine different graphite modifications and to determine the opaquephases within the Almahatta Sitta (AS) meteorite. Our investigationfocused on specimens AS39 and AS4. Both are multicomponent breccias,composed of different meteoritic lithologies, that is, anomalouspolymict ureilite material, different types of chondrites, and an ironmeteorite.[ 1-5 ] The mix of material implicates a crash of variableasteroids within time and space. This means that a primary ureiliticasteroid body has been the target of multiple meteorite or asteroidimpacts, which did not completely destroy the asteroid but added newmaterial (from chondritic to iron) to the main mass. For instance,Gabriel and Pack[ 6 ] suggested that the vein metal of monomictureilites is introduced by the impact of a Ni-poor iron meteorite in asimilar scenario as described above. Raman spectroscopy helped toinvestigate different carbon materials, that is, graphite and diamond.We used single-spectrum acquisition and spatial mappings to identify thedifferent modifications. Furthermore, we classified minor opaque phasessuch as schreibersite, suessite, daubreelite, cohenite, and kamacite.The investigation of these opaque phases is dealt with in furtherpapers.[1,2]