Nazarovite, Ni12P5, a new terrestrial and meteoritic mineral structurally related to nickelphosphide, Ni3P

Abstract

Nazarovite, Ni12P5, is a new natural phosphide discovered on Earth and in meteorites. Terrestrial nazarovite originates from phosphide assemblages confined to pyrometamorphic suite of the Hatrurim Formation (the Mottled Zone), the Dead Sea basin, Negev desert, Israel. Meteoritic nazarovite was identified among Ni-rich phosphide precipitates extracted from the Marjalahti meteorite (main group pallasite). Terrestrial mineral occurs as micrometer-sized lamella intergrown with transjordanite (Ni2P). Meteoritic nazarovite forms chisel-like crystals up to 8 μm long. The mineral is tetragonal, space group I4/m. The unit-cell parameters of terrestrial and meteoritic material, respectively: a 8.640(1) and 8.6543(3), c 5.071(3), and 5.0665(2) Å, V 378.5(2), and 379.47(3) Å3, Z = 2. The crystal structure of terrestrial nazarovite was solved and refined on the basis of X-ray single-crystal data (R1 = 0.0516), whereas the structure of meteoritic mineral was refined by the Rietveld method using an X-ray powder diffraction profile (RB = 0.22%). The mineral is structurally similar to phosphides of schreibersite–nickelphosphide join, Fe3P-Ni3P. Chemical composition of nazarovite (terrestrial/meteoritic, electron microprobe, wt%): Ni 81.87/78.59, Fe <0.2/4.10; Co <0.2/0.07, P 18.16/17.91, total 100.03/100.67, leading to the empirical formula Ni11.97P5.03 and (Ni11.43Fe0.63Co0.01)12.07P4.94, based on 17 atoms per formula unit. Nazarovite formation in nature, both on Earth and in meteorites, is related to the processes of Fe/Ni fractionation in solid state, at temperatures below 1100 °C.

Nickolayite, FeMoP, a new natural molybdenum phosphide

“…Nickolayite is the second terrestrial Mo-bearing phosphide, after polekhovskyite, MoNiP 2 (Britvin et al , 2022a). The mineral expands the series of natural phosphides belonging to the NiTiSi or Co 2 Si structure type (Table 9).…”

“…Natural terrestrial phosphides are one such unique feature of these rare mineral assemblages (Britvin et al , 2015). The majority of phosphides discovered in the Hatrurim Formation belong to the system Fe–Ni–P (Britvin et al , 2017a; 2019a,b; 2020a,b,c; 2022a). However, recent exploration has discovered a series of molybdenum-bearing phosphides (Britvin et al , 2022b).…”

Discovery of terrestrial andreyivanovite, FeCrP, and the effect of Cr and V substitution on the low-pressure barringerite-allabogdanite transition

“…The Hatrurim Complex has recently become known as a source of terrestrial phosphides (Britvin et al 2015). Here, besides the phosphides typical of meteorites: schreibersite, Fe 3 P (Britvin et al 2021a), barringerite, Fe 2 P (Britvin et al 2017) and its high-pressure analogallobogdanite (Britvin et al 2021b), nine new phosphides: halamishite, Ni 5 P 4 (Britvin et al 2020a); negevite, NiP 2 (Britvin et al 2020b); nazarovite, Ni 12 P 5 (Britvin et al 2022a); zuktamrurite, FeP 2 (Britvin et al 2019a); transjoardanite, Ni 2 P (Britvin et al 2020c); polekhovskyite, MoNiP 2 (Britvin et al 2022b); murashkoite, FeP (Britvin et al 2019b); nickolayite, FeMoP (Murashko et al 2019); orishchinite, Ni 2 P (Britvin et al 2019c) were discovered. This detection of phosphides in the rocks of the Hatrurim Complex is unexpected.…”