First high-resolution synchrotron X-ray study of icosahedrite, a natural quasicrystal from the Khatyrka meteorite

Quasicrystals are long-range-ordered materials with rotational symmetry incompatible with periodicity. Takakura et al. [(2025). IUCrJ 12, 435-443] present a study of a single grain of icosahedrite, the first natural icosahedral quasicrystal, which was found in a meteorite in 2009. Through detailed analysis of the diffraction peaks, they conclude that natural AlCuFe is an icosahedral quasicrystal superimposed by a phasonic modulation along the fivefold directions, which is similar to that observed in the synthetic quasicrystal. Based on knowledge of the synthesis and phase stability of icosahedral AlCuFe, they discuss the formation of icosahedrite in the meteorite.