Y.G. Liu, Haijun Cao, Rui Li, Jian Chen, Can Bin Yin, Ziyi Jia, X. Lu, Le Qiao, Xiaohui Fu, Changqing Liu, Chen Li, Yanqing Xin, Ying‐Bo Lu, Xiaojia Zeng, Jianzhong Liu, Yang Li, Zongcheng Ling
Lunar materials were believed to have formed and been preserved in a reducing environment, with only Fe 2+ and Fe 0 present. Native oxidized minerals, such as hematite, have not been validated in previously returned lunar samples. In this work, we report the discovery of micrometer-scale crystalline Fe 2 O 3 in the forms of hematite (α-Fe 2 O 3 ) and maghemite (γ-Fe 2 O 3 ) overgrowing troilite in the recently returned Chang’e-6 (CE6) lunar soils. It is possible that impact-induced oxygen release created localized micrometer-scale regions of elevated oxygen fugacity, facilitating the formation of Fe 2 O 3 at temperatures between ~700° and 1000°C. This finding provides credible evidence for the presence of Fe 2 O 3 on the lunar surface, challenging the traditional understanding of lunar surface redox states. In addition, the Fe 2 O 3 in the form of maghemite may be the mineralogical reason for the generation of the magnetic anomalies observed around the South Pole–Aitken basin.