Discovery of first ruby-like crystals on Mars

 NASA rover found fluorescent ruby-like gems on Mars

NASA's Perseverance rover has made a surprising discovery on Mars, finding tiny crystals of corundum. The minerals which form rubies and sapphires were embedded in Martian pebbles. This marks the first time such gems have been spotted on the Red Planet. The hints of the mineral were first spotted by Ann Ollila and her colleagues at Los Alamos National Laboratory in New Mexico. The discovery was made using the SuperCam instrument on the Perseverance rover, which analysed rocks like Hampden River, Coffee Cove and Smiths Harbour. Small, ruby-like crystals embedded in Martian rocks, which may also hide sapphires created in the fury of meteorite impacts. NASA's Perseverance rover found evidence of ruby-like crystals in a rock named Coffee Cove along with two others, a gemological first on the Red Planet. Mars is hiding a clutch of ruby-like crystals in its rocks, observations from the Perseverance rover suggest, and astronomers say other precious minerals, like sapphires, could exist across the Red Planet, too.

The Perseverance rover has found precious stones inside Martian pebbles. These gem grains are made of a substance called corundum, which is also known as ruby or sapphire depending on the traces of metals within it. Ann Ollila at Los Alamos National Laboratory in New Mexico and her colleagues first spotted hints of corundum while using Perseverance’s SuperCam instrument to examine a rock called Hampden River. SuperCam has several different ways to test a material’s composition, using two different lasers to either burn off its surface or provoke luminescence, then two cameras to examine the resulting light. In both tests, the results for Hampden River were nearly identical to the results from rubies measured in the lab, indicating the presence of tiny grains of corundum in the rock. An international team of researchers presented the findings, based on observations from spring 2025, March 16 at the 57th Lunar and Planetary Science Conference in Texas. These findings are currently under peer review. The story begins a short time ago on a planet not too far away, when a roving robot the size of a compact car climbed the side of a 4 billion-year-old impact crater and began exploring its rim. On that ancient and stony rim, NASA's Perseverance rover found a curious scattering of pale-colored "float rocks", out-of-place rocks which must have been transported there by impacts, geological activity or hydrological processes.

The results showed tiny grains of corundum, less than 0.2 mm's across, which shone brightly when hit with a laser. Unlike Earth, Mars doesn't have plate tectonics, so the corundum likely formed when meteorites smashed into the ground, heating and compressing the dust. As scientists often do when faced with a curious specimen, they blasted it with a laser, specifically, the green laser from the Perseverance rover's SuperCam, situated atop its mast. This laser excites minerals, causing them to emit light at specific wavelengths. And because every element and compound emits certain wavelengths of light, this reveals a sample's chemical composition. It's also likely that the crystals formed under different conditions than those on our planet. On Earth, corundum is created through metamorphic and igneous processes, in which intense heat and pressure, facilitated by tectonic activity, transform existing rocks into potential gemstones. But because there is no conclusive evidence for plate tectonics on Mars, the researchers suggest that the ruby-like crystals on the Red Planet may have formed through cosmic impacts. "The impacts provide high temperatures and high pressures, which can produce corundum. Hydrothermal fluids are also generated," Payré explained. Yet the researchers must find additional samples, at their origin, to describe their formation mechanism. "As of now, the corundum crystals were found in small pebbles that are coming from elsewhere, i.e., they are out of context. It is therefore difficult to constrain the full story," Payré said.

"[Corundum] usually is associated, on Earth, with tectonism. It's a very specific environment - you have to have a very silica-poor environment, very aluminium-rich," as quoted, Ollila said. "I was very surprised," Allan Treiman of the Lunar and Planetary Institute in Texas said during the conference session. The analysis showed that three of the laser-blasted float rocks exhibited clear signatures of the mineral corundum, with inclusions of the element chromium, crystals which match the chemical description of rubies. However, because the crystals are too small to be seen by Perseverance's imager, and their exact chemical composition is uncertain, the researchers aren't sure whether they have truly found Martian rubies or perhaps some other type of corundum. "The different types of corundum are based on the chemistry," study co-author Valerie Payré, a planetary geologist at the University of Iowa. "Although corundum is Al2O3, there are minor elements like chromium, titanium, and iron that can be present." The match is nearly identical. "These elements will provide the color to the mineral, and the name of it," Payré added. "We cannot quantify the amount of chromium, and other elements like iron and titanium might be present too. It is thus difficult to conclude whether they are rubies or other types of corundum [like sapphires]." The team ultimately classified the crystals as corundum and declined to guess about the variety without more chemical evidence.

Corundum is a mineral made of aluminum and oxygen. It is one of the hardest known natural substances, approaching the toughness of diamonds. Pure corundum is colorless, but microscopic impurities imbue it with brilliant hues. Iron or titanium inclusions yield brilliant blue sapphires, while chromium produces even rarer, resplendent rubies. As of now, the corundum crystals were found in small pebbles which are coming from elsewhere, i.e., they are out of context. However, anyone holding out hope for a future Martian-gemstone-studded necklace may be disappointed. The corundum crystals found within the float rocks are tiny,  less than 0.2 mm's (0.008 inches) in diameter. Could slightly larger Martian rubies exist? "Yes, possibly," study co-author Olivier Beyssac, a senior scientist at the French National Center for Scientific Research said. "Anyway corundum is pretty rare on Earth and rarely present as big crystals so one could expect the same on Mars." Rubies are far from the only spectacular stones found at Jezero crater, and further research may reveal sapphire-like stones there as well. In the past, scientists also discovered signs of other potential gemstones elsewhere on Mars, including quartz and opal, suggesting that our red planetary neighbor is a gem laboratory. "In retrospect, one might not have been, because there are aluminium-rich outcrops elsewhere on the planet and there are impacts, but I thought it was very shocking to see this. I would love to be able to pick one of those up and analyse it and see if it looks red - it's pretty disappointing that all you can see is this white pebble," Ollila said, further adding that when they were hit with the SuperCam laser, they shone brightly. This discovery provides new insights into Mars' geological history and suggests the planet has remained chemically and thermally active more recently than previously believed by us.