Kishonite, VH2, and Oreillyite, Cr2N, Two New Minerals from the Corundum Xenocrysts of Mt Carmel, Northern Israel

Abstract

Here, we describe two new minerals, kishonite (VH2) and oreillyite (Cr2N), found in xenoliths occurring in pyroclastic ejecta of small Cretaceous basaltic volcanoes exposed on Mount Carmel, Northern Israel. Kishonite was studied by single-crystal X-ray diffraction and was found to be cubic, space group Fm3¯m, with a = 4.2680(10) Å, V = 77.75(3) Å3, and Z = 4. Oreillyite was studied by both single-crystal X-ray diffraction and transmission electron microscopy and was found to be trigonal, space group P3¯1m, with a = 4.7853(5) Å, c = 4.4630(6) Å, V = 88.51 Å3, and Z = 3. The presence of such a mineralization in these xenoliths supports the idea of the presence of reduced fluids in the sublithospheric mantle influencing the transport of volatile species (e.g., C, H) from the deep Earth to the surface. The minerals and their names have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2020-023 and 2020-030a).

Evidence of the anthropogenic origin of the ‘Carmel sapphire’ with enigmatic super-reduced minerals

“…Mineral separates (concentrates) mined by the Shefa Yamim Company (https://www.shefagems.com ) as a result of exploration for gemstones in alluvial deposits are a source of this corundum. Osbornite in the corundum aggregates is associated with unusual SR minerals represented by nitrides, carbides, silicides, FeSi(Ti,Cr,V)-alloys, and Ti 3+ -bearing oxides (Griffin et al, 2016(Griffin et al, , 2018(Griffin et al, -2021Bindi et al, 2020). This corundum with inclusions of SR minerals obtained the trademark "Carmel sapphire" and has been the host of 10 new mineral species discovered in the last five years: carmeltazite (IMA2018-103) ZrAl2Ti4O11 (Griffin et al, 2018); kishonite (IMA2020-023) VH2 (Bindi et al, 2020); oreillyite (IMA 2020-030a) Cr2N (Bindi et al, 2020); griffinite (IMA 2021-110) Al2TiO5 ; magnéliite (IMA2021-111) Ti 3+ 2Ti 4+…”

“…2O7 (Ma et al, 2021); ziroite (IMA2022-013) ZrO2 ; sassite (IMA2022-014) Ti 3+ 2Ti 4+ O5 ; mizraite-(Ce) (IMA2022-027) Ce(Al11Mg)O19 ; toledoite (IMA2022-036) TiFeSi ; and yeite (IMA2022-079) TiSi . Grain aggregates of CS (and also hibonite and moissanite) from Carmel have been the objects of numerous scientific publications (Griffin et al, 2016(Griffin et al, , 2018(Griffin et al, -2022Xiong et al, 2017; https://doi.org/10.1180/mgm.2023.25 Published online by Cambridge University Press Dobrzhinetskaya et al, 2018;Cámara et al, 2019;Bindi et al, 2019Bindi et al, , 2020Huang et al, 2020;Stan et al, 2020;Oliveira et al, 2021;Lu et al, 2022), in which the authors present the highly controversial hypothesis that the corundum rock with SR minerals formed at the crust-mantle boundary as a result of CH4+H2 fluid flowing through the magmatic melt.…”

“…com) as a result of exploration for gemstones in alluvial deposits are a source of this corundum. Osbornite in the corundum aggregates is associated with unusual super-reduced minerals represented by nitrides, carbides, silicides, FeSi(±Ti,Cr,V)-alloys, and Ti 3+ -bearing oxides (Griffin et al, 2016b(Griffin et al, , 2018(Griffin et al, , 2019a(Griffin et al, ,b, 2020a(Griffin et al, ,b, 2021aBindi et al, 2020).…”

“…Mineral separates (concentrates) mined by the Shefa Yamim Company () as a result of exploration for gemstones in alluvial deposits are a source of this corundum. Osbornite in the corundum aggregates is associated with unusual super-reduced minerals represented by nitrides, carbides, silicides, FeSi(±Ti,Cr,V)-alloys, and Ti 3+ -bearing oxides (Griffin et al , 2016b, 2018, 2019a,b, 2020a,b, 2021a,b; Bindi et al , 2020).

Figure 1.Localities of osbornite findings in Israel.

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“…This corundum with inclusions of super-reduced minerals obtained the trademark ‘Carmel sapphire’ and has been the host of 10 new mineral species discovered in the last five years and approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA): carmeltazite (IMA2018-103) ZrAl 2 Ti 4 O 11 (Griffin et al , 2018); kishonite (IMA2020-023) VH 2 (Bindi et al , 2020); oreillyite (IMA 2020-030a) Cr 2 N (Bindi et al , 2020); griffinite (IMA 2021-110) Al 2 TiO 5 (Ma et al , 2022a); magnéliite (IMA2021-111) Ti 3+ 2 Ti 4+ 2 O 7 (Ma et al , 2022b); ziroite (IMA2022-013) ZrO 2 (Ma et al , 2022c); sassite (IMA2022-014) Ti 3+ 2 Ti 4+ O 5 (Ma et al , 2022d); mizraite-(Ce) (IMA2022-027) Ce(Al 11 Mg)O 19 (Ma et al , 2022e); toledoite (IMA2022-036) TiFeSi (Ma et al , 2022f); and yeite (IMA2022-079) TiSi (Ma et al , 2023). Grain aggregates of Carmel sapphire (and also hibonite and moissanite) from Carmel have been the objects of numerous scientific publications (Griffin et al , 2016a,b, 2018, 2019a,b, 2020a,b, 2021a,b, 2022; Xiong et al , 2017; Dobrzhinetskaya et al , 2018; Cámara et al , 2019; Bindi et al , 2019, 2020; Huang et al , 2020; Stan et al , 2020; Oliveira et al , 2021; Lu et al , 2022), in which the authors present the highly controversial hypothesis that the corundum rock with super-reduced minerals formed at the crust–mantle boundary as a result of CH 4 +H 2 fluid flowing through the magmatic melt.…”