Human bone probed by neutron diffraction: the burning process

The first neutron diffraction study of human burned bone is reported, aiming at a comprehensive elucidation of the heat-induced bone diagenesis process. Chemical and crystallinity changes were probed in different types of bone (femur, humerus and tibia) upon heating to different maximum temperatures (from 400 to 1000 degrees C, under aerobic conditions). Fourier transform infrared spectroscopy has provided valuable complementary information. Noticeable crystallographic and domain size variations were detected, mainly between 700 and 900 degrees C, the high temperature interval (>700 degrees C) corresponding to an organized, highly symmetric inorganic bone matrix, virtually devoid of carbonates and organic constituents, while the lower range (<700 degrees C) revealed a considerably lower crystallinity associated with the presence of carbonates, lipids and collagen. This work contributes to a better understanding of heat-induced changes in bone and is therefore relevant for archaeology, biomaterials and forensic science.