Mars Rover Finds Potential ‘Rubies’ and Other Gems on Red Planet

Mars may be hiding a glittering secret within its ancient rocks: evidence of ruby-like crystals, and potentially other gemstones like sapphires. Observations from NASA’s Perseverance rover, presented at the 57th Lunar and Planetary Science Conference in Texas on March 16, 2026, reveal spectral signatures consistent with corundum – the mineral that forms rubies and sapphires on Earth – within rocks at the edge of Jezero Crater. Whereas the findings, currently under peer review for publication in Geophysical Research Letters, don’t confirm the presence of fully formed gemstones, they open a fascinating new line of inquiry into the Red Planet’s geological history and potential for harboring unexpected mineral wealth.

Unearthing Clues in Jezero Crater

The discovery stems from the rover’s exploration of “float rocks” – rocks dislodged from their original location by impacts, geological activity, or ancient water flows – along the rim of Jezero Crater, a 4 billion-year-aged impact basin believed to have once held a lake. Perseverance’s SuperCam instrument, a sophisticated laser-based chemical analyzer, was used to examine three rocks – Hampden_River, Coffee_Cove, and Smiths_Harbour – revealing unexpected spectral signals. When the SuperCam laser vaporizes a tiny portion of a rock’s surface, the resulting plasma emits light at wavelengths specific to the elements and compounds present. It was this analysis that detected the telltale signs of corundum, specifically the presence of trivalent chromium (Cr³⁺) inclusions.

“The different types of corundum are based on the chemistry,” explains Valerie Payré, a planetary geologist at the University of Iowa and co-author of the study. “Although corundum is Al₂O₃, You’ll see minor elements like chromium, titanium, and iron that can be present.” The specific combination of these elements determines the color and variety of corundum – chromium yielding rubies, iron and titanium creating sapphires, and the absence of these impurities resulting in colorless corundum.

Corundum on Mars: A Geological Puzzle

The presence of corundum on Mars is intriguing because the conditions under which it typically forms on Earth – deep within the crust under intense heat and pressure – are not readily apparent on the Red Planet. Earth’s plate tectonics play a crucial role in creating these conditions, but Mars lacks evidence of active plate tectonics. This has led researchers to hypothesize that cosmic impacts may be responsible for the formation of corundum on Mars. The immense heat and pressure generated by meteorite strikes could provide the necessary energy to transform existing rocks into the gemstone mineral.

Yet, the corundum crystals detected by Perseverance are exceedingly small – less than 0.2 millimeters in diameter – making definitive identification challenging. The rover’s imaging systems lack the resolution to visually confirm their crystalline structure. The float rock origin means the crystals are found “out of context,” as Payré notes, making it demanding to reconstruct the precise geological processes that led to their formation.

The team’s findings build on previous discoveries within Jezero Crater, including the detection of quartz, another mineral often associated with past water activity. These discoveries collectively suggest that Jezero Crater was once a dynamic environment with a complex geological history.

Beyond Rubies: The Potential for Other Gemstones

While the current findings focus on corundum, the possibility of other gemstones existing on Mars cannot be ruled out. Scientists have also identified signs of opal within the crater, further hinting at a diverse mineral composition. Olivier Beyssac, a senior scientist at the French National Center for Scientific Research, suggests that larger Martian rubies or sapphires could potentially exist, though corundum is generally rare even on Earth and rarely forms in large crystals.

The discovery of corundum also raises questions about the potential for past habitability on Mars. While corundum itself is not a biosignature, its formation often involves hydrothermal fluids – water heated by volcanic activity or impacts – which could have provided a favorable environment for microbial life. Perseverance’s primary mission is to search for signs of ancient life, and the presence of these minerals adds another layer of complexity to the search.

What’s Next for Martian Mineralogy?

The Perseverance rover continues to explore Jezero Crater, collecting rock and soil samples for potential return to Earth as part of the Mars Sample Return campaign. These samples will undergo detailed analysis in terrestrial laboratories, providing scientists with a much more comprehensive understanding of Martian geology and the potential for past life. The analysis of these samples will be crucial for confirming the presence of corundum and other gemstones, determining their precise chemical composition, and unraveling the mysteries of their formation.

Further research will also focus on identifying the specific mechanisms responsible for corundum formation on Mars. Was it primarily driven by cosmic impacts, or did other geological processes play a role? Answering these questions will require a combination of remote sensing data, rover-based observations, and laboratory analysis of Martian samples. The ongoing exploration of Mars promises to reveal even more surprising discoveries about our planetary neighbor, and perhaps, a hidden treasure trove of gemstones.

You can learn more about the Mars 2020 Perseverance rover mission on the NASA website.