Miller Range 07687 and its place within the CM‐CO clan

Miller Range (MIL) 07687 is a peculiar carbonaceous chondrite officially classified as CO3. However, it has been found to display unique petrographic properties that are atypical of this group. Moreover, Raman spectra its polyaromatic matter does not reflect structural order consistent with the metamorphic history type 3 chondrite. As result, suggested be an ungrouped C2 CO affinities, although fully excluded The ambiguity meteorite classification motivation behind present study. We conclude MIL possible affinities CO, CM and/or some chondrites. difficulty in classifying stems from (i) heavily weathered nature, which interferes interpretation our oxygen (O-)isotopic measurements (ii) overlap and O-isotopic descriptions various COs, CMs meteorites Meteoritical society database. Optical infrared unequilibrated nature indicate probably mildly aqueously altered. Despite traces aqueous alteration having previously described 07687, first time presence hydrated amorphous silicates reported. In fact, results show hydration beyond most CO3s, less than CM2s, comparable primitive CR2s. Consequently, we support s ung label, CO2 or CM2 cannot excluded.