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South African Diamonds Reveal Surprising Mantle Chemistry

9/23/2025

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Summary

Story summary

Diamonds from Voorspoed, South Africa, provide the first natural evidence of nickel-rich alloys in Earth's mantle.
Inclusions of nickel-iron alloys and nickel-rich carbonates reveal a redox-freezing reaction at 280–470 km depth.
This implies oxidized melts can exist deeper than thought, affecting diamond formation and mantle dynamics.
Yael Kempe and Yaakov Weiss led the study from the Hebrew University of Jerusalem.

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Story summary

Diamonds from Voorspoed, South Africa, provide the first natural evidence of nickel-rich alloys in Earth's mantle.
Inclusions of nickel-iron alloys and nickel-rich carbonates reveal a redox-freezing reaction at 280–470 km depth.
This implies oxidized melts can exist deeper than thought, affecting diamond formation and mantle dynamics.
Yael Kempe and Yaakov Weiss led the study from the Hebrew University of Jerusalem.