New Minerals from Inclusions in Corundum Xenocrysts from Mt. Carmel, Israel: Magnéliite, Ziroite, Sassite, Mizraite-(Ce) and Yeite

Chi Ma; Fernando Cámara; Luca Bindi; Vered Toledo; William L Griffin

doi:10.3390/ma16247578

New Minerals from Inclusions in Corundum Xenocrysts from Mt. Carmel, Israel: Magnéliite, Ziroite, Sassite, Mizraite-(Ce) and Yeite

Materials (Basel). 2023 Dec 9;16(24):7578. doi: 10.3390/ma16247578.

Authors

Chi Ma¹, Fernando Cámara², Luca Bindi³, Vered Toledo⁴, William L Griffin⁵

Affiliations

¹ Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
² Dipartimento di Scienze della Terra "A. Desio", Università degli Studi di Milano, Via Mangiagalli 34, I-20133 Milan, Italy.
³ Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via La Pira 4, I-50121 Florence, Italy.
⁴ Shefa Gems (A.T.M.) Ltd., Netanya 4210602, Israel.
⁵ ARC Centre of Excellence for Core to Crust Fluid Systems and GEMOC, Earth and Environmental Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia.

Abstract

Our nanomineralogical investigation of melt inclusions in corundum xenocrysts from the Mt. Carmel area, Israel has revealed seven IMA-approved new minerals since 2021. We report here four new oxide minerals and one new alloy mineral. Magnéliite (Ti³⁺₂Ti⁴⁺₂O₇; IMA 2021-111) occurs as subhedral crystals, ~4 μm in size, with alabandite, zirconolite, Ti,Al,Zr-oxide, and hibonite in corundum Grain 767-1. Magnéliite has an empirical formula (Ti³⁺_1.66Al_0.13Ti⁴⁺_0.15Mg_0.10Ca_0.01Sc_0.01)_Σ2.06 (Ti⁴⁺_1.93Zr_0.08)_Σ2.01O₇ and the triclinic P1¯ Ti₄O₇-type structure with the cell parameters: a = 5.60(1) Å, b = 7.13(1) Å, c = 12.47(1) Å, α = 95.1(1)°, β = 95.2(1)°, γ = 108.7(1)°, V = 466(2) Å³, Z = 4. Ziroite (ZrO₂; IMA 2022-013) occurs as irregular crystals, ~1-4 μm in size, with baddeleyite, hibonite, and Ti,Al,Zr-oxide in corundum Grain 479-1a. Ziroite has an empirical formula (Zr_0.72Ti⁴⁺_0.26Mg_0.02Al_0.02Hf_0.01)_Σ1.03O₂ and the tetragonal P4₂/nmc zirconia(HT)-type structure with the cell parameters: a = 3.60(1) Å, c = 5.18(1) Å, V = 67.1(3) Å³, Z = 2. Sassite (Ti³⁺₂Ti⁴⁺O₅; IMA 2022-014) occurs as subhedral-euhedral crystals, ~4-16 μm in size, with Ti,Al,Zr-oxide, mullite, osbornite, baddeleyite, alabandite, and glass in corundum Grain 1125C1. Sassite has an empirical formula (Ti³⁺_1.35Al_0.49Ti⁴⁺_0.08Mg_0.07)_Σ1.99(Ti⁴⁺_0.93Zr_0.06Si_0.01)_Σ1.00O₅ and the orthorhombic Cmcm pseudobrookite-type structure with the cell parameters: a = 3.80(1) Å, b = 9.85(1) Å, c = 9.99(1) Å, V = 374(1) Å³, Z = 4. Mizraite-(Ce) (Ce(Al₁₁Mg)O₁₉; IMA 2022-027) occurs as euhedral crystals, <1-14 μm in size, with Ce-silicate, Ti-sulfide, Ti,Al,Zr-oxide, ziroite, and thorianite in corundum Grain 198-8. Mizraite-(Ce) has an empirical formula (Ce_0.76Ca_0.10La_0.07Nd_0.01)_Σ0.94(Al_10.43Mg_0.84Ti³⁺_0.60Si_0.09Zr_0.04)_Σ12.00O₁₉ and the hexagonal P6₃/mmc magnetoplumbite-type structure with the cell parameters: a = 5.61(1) Å, c = 22.29(1) Å, V = 608(2) Å³, Z = 2. Yeite (TiSi; IMA 2022-079) occurs as irregular-subhedral crystals, 1.2-3.5 μm in size, along with wenjiite (Ti₅Si₃) and zhiqinite (TiSi₂) in Ti-Si alloy inclusions in corundum Grain 198c. Yeite has an empirical formula (Ti_0.995Mn_0.003V_0.001Cr_0.001)(Si_0.996P_0.004) and the orthorhombic Pnma FeB-type structure with the cell parameters: a = 6.55(1) Å, b = 3.64(1) Å, c = 4.99(1) Å, V = 119.0(4) Å³, Z = 4. The five minerals are high-temperature oxide or alloy phases, formed in melt pockets in corundum xenocrysts derived from the upper mantle beneath Mt. Carmel.

Keywords: Ce(Al11Mg)O19; Israel; Mt. Carmel; Ti3+2Ti4+2O7; Ti3+2Ti4+O5; TiSi; ZrO2; corundum; magnéliite; mizraite-(Ce); new minerals; sassite; yeite; ziroite.

Grants and funding

The research was funded by MIUR-PRIN2017, project “TEOREM deciphering geological processes using Terrestrial and Extraterrestrial ORE Minerals”, prot. 2017AK8C32 (PI: Luca Bindi).