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Rare Diamonds Challenge Deep Earth Chemistry Theories

9/27/2025

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Summary

Story summary

Two diamond samples from a South African mine reveal unusual inclusions, signaling deep mantle processes.
The inclusions combine oxidized carbonate minerals and reduced nickel alloys, a pairing once thought incompatible.
At depths of 280 to 470 kilometers, the diamonds form from deep-earth reactions, challenging prior mantle-chemistry theories.
The findings also address nickel atoms substituting for carbon in diamond lattices.

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Story summary

Two diamond samples from a South African mine reveal unusual inclusions, signaling deep mantle processes.
The inclusions combine oxidized carbonate minerals and reduced nickel alloys, a pairing once thought incompatible.
At depths of 280 to 470 kilometers, the diamonds form from deep-earth reactions, challenging prior mantle-chemistry theories.
The findings also address nickel atoms substituting for carbon in diamond lattices.