NASA's Perseverance rover has identified corundum on Mars for the first time — the mineral that, on Earth, forms rubies and sapphires. The detection was made by the SuperCam instrument in three pale rocks on the rim of Jezero Crater and detailed by NASA in an article published on November 9, 2026.
This does not mean collectible rubies scattered across the Martian soil. What the rover found were microscopic grains of chromium-bearing corundum — the same chemical signature that gives ruby its red color — trapped inside fist-sized pale rocks. The rover's cameras could not see the grains: they measure less than 200 to 375 micrometers.
How SuperCam's laser revealed the mineral
SuperCam fires a green laser at rocks and analyzes the returning light. Using time-resolved luminescence, the team noticed two strong, narrow peaks at 692.7 and 694.1 nanometers, with a glow lasting about 3 milliseconds. That is the signature of chromium replacing aluminum in the corundum structure — the same mechanism that colors ruby.
The three rocks — named Hampden River, Coffee Cove and Smiths Harbour — were analyzed in March, April and July 2025. All are loose “float rocks”, made mostly of plagioclase, an aluminum silicate. The results were published in Geophysical Research Letters by a team led by geochemist Ann Ollila of Los Alamos National Laboratory.
Why corundum on Mars should not be there
On Earth, corundum forms in aluminum-rich, silica-poor settings, usually linked to metamorphism and pegmatitic rocks — processes often tied to plate tectonics. Mars has no plate tectonics. Finding corundum on the planet is, in the team's words, “very unexpected”.
The authors' preferred hypothesis is the impact that opened Jezero Crater itself, 45 kilometers wide, in the Noachian period: prolonged heating from the impact would have created localized metamorphism, forming the mineral. Because the analyzed rocks are loose fragments whose source outcrop has not been located, the interpretation remains an inference — and the authors point the way forward: find the outcrop, collect a core sample and bring it back to Earth.
What the discovery of corundum on Mars changes
Beyond expanding the catalog of minerals identified on Mars, the detection of corundum on Mars shows the rover carries an unexpected tool: time-resolved luminescence, now used frequently on pale rocks to look for more evidence of ancient impact effects. The mission team already applies the technique regularly while exploring the ancient terrain near Jezero's rim.
Image credit: self-portrait of the Perseverance rover at Rochette, Mars, in September 2021. Image: NASA/JPL-Caltech, via Wikimedia Commons.
Sources
- NASA Science — “Rubies on Mars?”, by Roger C. Wiens, SuperCam Principal Investigator (November 9, 2026): science.nasa.gov/blog/rubies-on-mars
- Phys.org — “Ruby-forming mineral found by Mars rover hints at violent impacts” (August 18, 2026): phys.org
- Ollila, A. M. et al. (2026). “Corundum Discovered by SuperCam and the Perseverance Rover at Jezero Crater, Mars”, Geophysical Research Letters. DOI: 10.1029/2026GL122537
- ScienceAlert — “'Very Unexpected': NASA Rover Zapped a Rock on Mars And Found a Gemstone Surprise”: sciencealert.com
Transparency: this article was produced with the help of artificial intelligence, cross-checking public sources on the internet. The information was verified in NASA's official blog, in independent coverage and in the peer-reviewed scientific paper. Always consult the original sources.
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