Surface elemental composition of Ryugu particles A0226 and C0242 obtained from XPS measurements. Elemental abundances obtained from high-resolution photoelectron spectra, expressed as A0226/C0242 ratio (in atomic percent). Elements are ordered from left to right by decreasing 50% condensation temperature (B. J. Wood et al. 2019). An A0226/C0242 atomic percentage ratio greater than 1 indicates enrichment on the A0226 surface. Sulfur data were excluded in this diagram since they were below the detection limit in the C0242 particle. All data sources are given in the Appendix data section, and error bars are smaller than symbols.