Evidence of np-Fe⁰ particles produced by H⁺ irradiation. (a) Analysis result of EDS line scan for an np-Fe⁰ particle in Ol-76-H; the red line represents the location of EDS line scanning, and the dashed red circle is the location of the np-Fe⁰ particle. (b) HRTEM image of np-Fe⁰ particles in Ol-76-H. The lower left corner indicates the position where the main image (b) was acquired. The top right corner shows an enlarged image of the np-Fe⁰ particle and its corresponding fast Fourier transform (FFT) image. (c–i) Np-Fe⁰ particles in Ol-76-H, Ol-68-H, Ol-45-H, and Px-52-H identified by EELS. The minerals’ unirradiated areas were used for internal standards, and np-Fe⁰ particles in native space weathering rims were used for external standards to distinguish the valence states of iron.