Infrared Absorption\nSpectrum of α‑Moganite\nfrom First-Principles

α-Moganite is a polymorph of silicon dioxide that,\ntogether\nwith α-quartz, comprises the inorganic component of flint/cherta\nmaterial of overwhelming importance in archeology, anthropology, and\npaleontology. Whereas α-quartz has been studied extensively,\nboth theoretically and experimentally, α-moganite has received\nconsiderably less attention, possibly owing to an absence of pure-phase\nmaterial. In this study, we address this gap by providing a detailed\nfirst-principles analysis of the infrared (IR) absorption spectrum\nof α-moganite and its relation to the underlying structure.\nWe find that the 4-membered rings of silicon and oxygen atoms, that\ndo not appear in α-quartz, constitute a fundamental structural\nmotif of this mineral. This distinctive arrangement results in moganite-specific\nfingerprints in the IR spectrum of flint/chert. This opens the door\nto evaluation and quantification of α-moganite content in archeological\nsamples, providing insights into flint/chert raw material preferences\nand stone tool production by hominins.