In Meteoritics & Planetary Science for March (vol. 60, #3)
Sulfides (XSy, where X is typically a metal) are extremely common in CM- and CI-group carbonaceous chondrite meteorites. As Carbonaceous-type asteroids are presumed to be parent bodies producing meteorites, shouldn’t those asteroids also be sulfide-rich? Going by Ryugu (which looks like CI material), the answer is yes, and individual sulfide compositions and morphologies can tell us of their histories. In the case of Ryugu, the material never got baked by entering Earth’s atmosphere, nor weathered by exposure (even briefly) to Earth’s humidity, microbes, etc.
…and speaking of CI chondrites, the journal is Meteoritics… and other stuff too. Friedrich et al. review those few CI specimens (roughly five, some would argue for more, including the CY chondrites). What do we know about these crucial relics from the early Solar System, so that we may compare and contrast to Ryugu/Bennu samples?