Bridgmanite, MgSiO3 with perovskite structure, is considered the most abundant mineral on Earth. On the lower mantle, it contains Fe and Al that strongly influence its behavior. Experimentalists have debated whether iron may exist in a mixed valence state, coexistence of Fe2+ and Fe3+ in bridgmanite, through charge disproportionation. Here, we report the discovery of Fe-rich aluminous bridgmanite coexisting with metallic iron in a shock vein of the Suizhou meteorite. This is the first direct evidence in nature of the Fe disproportionation reaction, which so far has only been observed in some high-pressure experiments. Furthermore, our discovery supports the idea that the disproportionation reaction would have played a key role in redox processes and the evolution of Earth.

中文翻译：

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地外桥状辉石中铁的电荷歧化的证据。

布里奇锰矿，具有钙钛矿结构的MgSiO3，被认为是地球上最丰富的矿物。在下地幔中，它含有强烈影响其行为的铁和铝。实验学家们争论了铁是否可能以混合价态存在，以及通过电荷歧化在桥锰矿中同时存在Fe2 +和Fe3 +。在这里，我们报道了随州陨石的冲击脉中发现了与金属铁共存的富铁铝水辉石。这是铁歧化反应本质上的第一个直接证据，到目前为止，仅在某些高压实验中才观察到。此外，我们的发现支持了歧化反应在氧化还原过程和地球演变中起关键作用的想法。