One of the rarest meteorites has fallen in Italy and opens up new horizons

15 May 2024

This content was first published on IGR – Italian Gemological Review no. 18 in 2024. The information provided here is therefore current as of the original publication date.

A finding that exemplifies a classic case of Citizen Science; a small spherule, was found on Mount Gariglione in Calabria, Italy, by a collector who, noticing its peculiar metallic luster, sent it to researchers at the University of Bari to investigate its enigmatic nature. Analyses promptly revealed an astonishing discovery: the spherule was a micrometeorite.

This discovery, a significant breakthrough investigation in planetary sciences, has been made by a team of Italian researchers from the University of Bari (Giovanna Agrosì, Daniela Mele, Gioacchino Tempesta, and Floriana Rizzo from the Department of Earth and Environmental Sciences), in collaboration with the University of Florence (Luca Bindi and Tiziano Catelani from the Department of Earth Sciences) and the Italian Space Agency (Paola Manzari).

Micrometeorite FB-A1 dal Monte Gariglione (Italia). a) Immagine SEM-BSE; b) rendering del volume micro-CT (in grigio chiaro le leghe Al-Cu e come piccole gocce luminose le leghe Fe-Ni disseminate nell'intero volume) — FB-A1 micrometeorite from Mt. Gariglione (Italy). a) SEM-BSE image; b) micro-CT volume rendering (in light gray the Al-Cu alloys and as small bright droplets the Fe-Ni alloys disseminated in the whole volume). (Photo: Agrosì, G., Manzari, P., Mele, D. et al. A naturally occurring Al-Cu-Fe-Si quasicrystal in a micrometeorite from southern Italy. Commun Earth Environ 5, 67 (2024). License CC BY 4.0 DEED)

This is an exceptionally rare meteorite, distinguished by the presence within it of a “quasicrystal” with icosahedral symmetry and chemical composition Al₅₂Cu₃₁Fe₁₀Si₇. This landmark discovery is detailed in an article published in the journal Communications Earth & Environment (https://doi.org/10.1038/s43247-024-01233-w | www.nature.com/commsenv), affiliated with the Nature-Portfolio group. The discovery proved to be extraordinary from the outset: it marks only the third instance worldwide of extraterrestrial material containing such metal alloys and the second discovery of a micrometeorite harboring a naturally occurring quasicrystal, following the 2011 revelation of the Khatyrka meteorite. The presence of such quasicrystals, solids defying traditional crystal symmetries, that are often created in labs, suggests their formation in high-velocity shock events. This breakthrough opens new avenues for understanding cosmic material compositions and the conditions under which these unique structures arise, shedding light on both extraterrestrial geology and the origins of quasicrystals themselves.

Gem News published on IGR – Italian Gemological Review #18, Spring 2024