Overview
- Researchers using high‑resolution microscopy and chemical microanalysis identified andradite, an iron‑rich garnet, in a fragment of Martian breccia NWA 8171 held at the Royal Ontario Museum.
- The garnet occurs in grains within a tiny 0.8 x 0.5 mm fragment and in individual particles smaller than a poppy seed, which explains why the mineral was nearly overlooked during initial inspection.
- The team first misidentified the particle as common pyroxene before detailed imaging and chemistry confirmed it as andradite.
- Scientists say the mineral could have formed under impact‑generated high pressure, from unusual magmatic processes on Mars, or arrived from elsewhere, and they plan isotopic tests to decide between those scenarios.
- Those isotope measurements would require destructive sampling, so the researchers have delayed that work because the meteorite fragment is exceptionally scarce, leaving new questions about Mars’s crustal history unresolved for now.