The Chang'e-6 samples returned in June 2024 contain tiny grains of hematite (Fe2O3), marking the first clear mineral evidence of oxidised iron on the Moon. The hematite occurs primarily in impact-bonded breccias from the South Pole–Aitken Basin, suggesting formation during large meteorite impacts. Scientists propose oxygen released from sulfide minerals during impacts reacted with native iron to form hematite. The discovery challenges the idea of a uniformly reducing lunar surface and may help explain local magnetic anomalies.
Chang'e-6 Finds 'Rust' on the Moon — First Direct Mineral Evidence of Hematite
The Chang'e-6 samples returned in June 2024 contain tiny grains of hematite (Fe2O3), marking the first clear mineral evidence of oxidised iron on the Moon. The hematite occurs primarily in impact-bonded breccias from the South Pole–Aitken Basin, suggesting formation during large meteorite impacts. Scientists propose oxygen released from sulfide minerals during impacts reacted with native iron to form hematite. The discovery challenges the idea of a uniformly reducing lunar surface and may help explain local magnetic anomalies.
04:11 PM, 11/17/2025Science
Hematite (Fe2O3) confirmed in lunar soil returned by Chang'e-6
Scientists report the first unambiguous mineral-scale evidence of hematite (Fe2O3) in lunar soil returned by China’s Chang'e-6 mission. The samples, brought to Earth in June 2024, include tiny hematite grains concentrated in breccias — rocks made of fragments fused together by the shock, heat and pressure of meteorite impacts.
The new results, published in Science Advances, build on earlier hints from remote sensing and from Chang'e-5 samples that showed traces of oxidised iron inside impact-produced glasses. The Chang'e-6 finding, however, is direct mineralogical evidence that strongly oxidised iron phases can form on the Moon.
"This finding provides credible evidence for the presence of Fe2O3 on the lunar surface, challenging the traditional understanding of the lunar surface," the authors write.
Researchers propose a plausible formation mechanism: large meteorite impacts liberate oxygen from oxygen-bearing minerals such as troilite and other sulfides. Under the extreme conditions of an impact, that oxygen can react with native iron in lunar rocks to form hematite — an impact-driven, localized oxidation process that resembles “rusting” but is driven by shock chemistry rather than Earth-like weathering.
The hematite grains were mainly identified in impact-bonded breccias from the South Pole–Aitken (SPA) Basin, a region known for large, ancient impacts. The study links this impact-driven oxidation process to major collision sites, including areas sampled by Apollo missions on the lunar far side.
Beyond its chemical significance, the discovery may also help explain puzzling magnetic anomalies observed in parts of the Moon, including the northwestern SPA region. Oxidised iron phases can influence local magnetic signatures, so their presence offers a potential new piece of the puzzle.
Why this matters
The finding changes our picture of the lunar surface from uniformly oxygen-poor to one in which localized, impact-driven oxidation can produce stable oxidised minerals. It highlights the importance of returned samples for revealing processes that remote sensing alone can miss, and it opens new questions about how impacts alter lunar materials and magnetic properties.
Key points: first mineral evidence of hematite on the Moon; formation likely driven by oxygen released from sulfides during large impacts; hematite concentrated in breccias from the SPA Basin; potential implications for lunar magnetism.