An overlooked fragment of the Santa Catharina ataxite

Abstract

Abstract— An undocumented mass of 28 kg, recovered from a museum collection, is examined by several methods: optical microscopy, scanning electron microscopy, X‐ray diffraction, Mössbauer spectroscopy and chemical analyses by atomic absorption, energy‐ and wavelength‐dispersive X‐ray spectrometry and, with respect to the trace elements Ir, As, Au, by neutron activation. The structure and the mineralogical chemical composition of the mass identify it as a fragment of the Santa Catharina iron meteorite from Brazil.

Allabogdanite, the high-pressure polymorph of (Fe,Ni)2P, a stishovite-grade indicator of impact processes in the Fe–Ni–P system

“…Accessory minerals in Santa Catharina are comprised of phosphides related to the schreibersite-nickelphosphide series, Fe 3 P–Ni 3 P 39,40 , sarcopside-like iron phosphate, Fe 3 (PO 4 ) 2 , and magnetite 39,41 . Troilite nodules up to a few centimeters across are very common 41 . Troilite, FeS, is partially substituted by pentlandite, (Ni,Fe) 9 S 8 , and unidentified nickel sulfides 41 .…”

“…Troilite nodules up to a few centimeters across are very common 41 . Troilite, FeS, is partially substituted by pentlandite, (Ni,Fe) 9 S 8 , and unidentified nickel sulfides 41 . Phosphide mineralization in Santa Catharina was investigated by several scientific groups using electron microprobe 39,41,42 , ion microprobe 43 and spatially resolved X-ray absorption spectroscopy 44 .…”

“…Troilite, FeS, is partially substituted by pentlandite, (Ni,Fe) 9 S 8 , and unidentified nickel sulfides 41 . Phosphide mineralization in Santa Catharina was investigated by several scientific groups using electron microprobe 39,41,42 , ion microprobe 43 and spatially resolved X-ray absorption spectroscopy 44 . Brandstätter and coauthors 42 reported the phosphide mineral corresponding to (Fe,Ni) 2 P and ascribed it to barringerite, the low-pressure polymorph of (Fe,Ni) 2 P 31 , based on its chemical composition.…”