I am conducting a research on some ancient kiln structures and I have found small black areas that, once under the microscope (binocular and SEM) are discrete round particles. They are composed of carbon and exhibit a clear complex structure. Moreover, they are compact. Thus they shouldn’t be identified as carbon cenospheres. Because of their size and composition, they could be spores, but I haven’t been able to identify them. I would appreciate if you could make any suggestion. Thank you in advance