¹Christopher D.K. Herd;²Chi Ma;¹Andrew J. Locock;¹Radhika Saini;³Erin L. Walton
American Mineralogist 109, 2142-2151 Open Access Link to Article [https://doi.org/10.2138/am-2023-9225]
¹Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
²Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, U.S.A.
³Department of Physical Sciences, MacEwan University, City Centre Campus, 10700 104 Avenue, Edmonton, Alberta T5J 4S2, Canada
Copyright: The Mineralogical Society of America

Petrologic investigation of the El Ali IAB iron meteorite (Somalia) revealed three new minerals: elaliite [Fe82+Fe³⁺(PO₄)O₈, IMA 2022-087], elkinstantonite [Fe₄(PO₄)₂O, IMA 2022-088], and olsenite [KFe₄(PO₄)₃, IMA 2022-100]. The name elaliite recognizes the occurrence of this mineral within the El Ali meteorite, originally located at 4° 17′ 17″N, 44° 53′ 54″E. Elkinstantonite is named after Linda (Lindy) Elkins-Tanton (b. 1965), a planetary scientist and professor in the School of Earth and Space Exploration at Arizona State University. The name olsenite is in honor of Edward J. Olsen (1927–2020), the former Curator of Mineralogy and Meteorites at the Field Museum of Natural History in Chicago (1960–1991). The new minerals and their names have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association. The holotype specimens of elaliite, elkinstantonite, and olsenite consist of the polished block mount with accession number MET11814/2-1/EP1 deposited in the University of Alberta Meteorite Collection. Elaliite, elkinstantonite, and olsenite occur along with wüstite, troilite, sarcopside, and Ca-bearing graftonite within inclusions in the iron-nickel metal (kamacite, 9.4 wt% Ni) that makes up the bulk of the El Ali sample. The empirical formulas determined by electron probe microanalysis for elaliite, elkinstantonite, and olsenite are: (⁠Fe7.9432+Fe1.0203+Cr_0.010Ni_0.006Ca_0.004Mn_0.004)_Σ8.987(P_0.932Si_0.077S_0.005)_Σ1.014O₁₂, (⁠Fe3.9472+Mn_0.016Ni_0.003Ca_0.001Cr_0.001)_Σ3.968(P_1.986Si_0.014S_0.013)_Σ2.013O₉, and (K_0.820Na_0.135Ca_0.004)_Σ0.959(Fe_3.829 Mn_0.050)_Σ3.879(P_2.972S_0.058Si_0.017)_Σ3.047O₁₂, respectively. Electron backscatter diffraction was used to confirm the crystal structures of the three new minerals. Raman spectra for all three minerals are also presented.