¹Lidia Pittarello,¹Stepan M. Chernonozhkin,¹Oscar Marchhart,¹Martin Martschini,¹Silke Merchel,¹Alexander Wieser,¹Frank Vanhaecke,¹Steven Goderis
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.70030]
¹Naturhistorisches Museum Wien (NHMW), Mineralogisch-Petrographische Abteilung, Vienna, Austria
²Departement für Lithosphärenforschung, Universität Wien, Vienna, Austria
³Atomic & Mass Spectrometry Research Unit, Department of Chemistry, Ghent University, Ghent, Belgium
⁴Faculty of Physics, Isotope Physics, University of Vienna, Vienna, Austria
⁵Archeology, Environmental Changes & Geo-Chemistry, Department of Chemistry, Vrije Universiteit Brussel, Brussels, Belgium
Published by arrangement with John Wiley & Sons

Planetary scientists heavily depend on meteorite curation facilities for the preparation and allocation of protected (e.g., Antarctic), highly valuable extraterrestrial specimens. In this work, a fragment of the Dyalpur ureilite obtained from a museum is discussed. The sample is found to contain microstructural, geochemical, and isotopic features inconsistent with any meteorite. The fragment consists of pargasitic amphibole, Ni-sulfides, and chromite grains in Fo₉₂ olivine groundmass, cut by serpentine veins. Amphibole geothermobarometry yields equilibrium conditions that are not compatible with the assumed ureilite parent body. Assuming the fragment represented a rare clast in an ureilite, further analyses were performed. Both the oxygen isotopic composition and the extremely low level of cosmogenic radionuclides confirm the terrestrial origin of the fragment; it is a partially serpentinized peridotite. This work stresses the importance of petrographic characterization of samples used for (isotope) geochemical analyses, of a well-documented sample curation, and of cosmogenic nuclide measurements for the unequivocal identification of extraterrestrial material. Finally, caution is recommended before making sensational claims in cases of anomalous results.