Toledoite, TiFeSi, a New Mineral from Inclusions in Corundum Xenocrysts from Mount Carmel, Israel

Abstract

During our nanomineralogical investigation of melt inclusions in corundum xenocrysts from the Mount Carmel area, Israel, seven new oxide and alloy minerals have been discovered since 2021. Herein, we report toledoite (TiFeSi; IMA 2022-036), a new alloy mineral. Toledoite occurs as irregular crystals 2–16 μm in size, with gupeiite (Fe3Si), jingsuiite (TiB2), ziroite (ZrO2), osbornite (TiN), xifengite (Fe5Si3), and naquite (FeSi) in corundum Grain WG1124E-1. Toledoite has an empirical formula (Ti0.83Cr0.07Mn0.06V0.02)(Fe0.96Mn0.04)(Si0.99P0.04) and an orthorhombic Ima2 TiFeSi-type structure with the following cell parameters: a = 7.00(1) Å, b = 10.83(1) Å, c = 6.29(1) Å, V = 477(1) Å3, Z = 12. Toledoite is a high-temperature alloy phase, formed under extremely reduced conditions in melt pockets in corundum xenocrysts derived from the upper mantle beneath Mount Carmel in Israel. The name was given in honor of Vered Toledo, of Shefa Gems Ltd. for her support and for providing corundum xenocrysts from the Mount Carmel region for this investigation of new minerals.

Keywords

• toledoite
• TiFeSi
• new mineral
• corundum
• Mount Carmel
• Israel