XRD AND CREMATED HUMAN REMAINS: WHAT IS IN THIS URN ANYHOW ?
In investigations of this type powder x-ray diffraction (XRD) can be utilized as a powerful forensic tool. XRD is used for identification of crystalline materials, including differentiating components of mixtures. The major mineral component of bone is calcium phosphate, which is similar in structure and composition to inorganic apatite group. Historically bioapatite was identified as hydroxy(l)apatite or carbonated hydroxy(l)apatite, but recent studies have shown that bone apatite does not have a high concentration of OH-. More detailed characterization of the structure of fresh bone and teeth is an area of active investigation, as the nanocrystalline (10s of nanometers) material is difficult to analyze and the flexible structure of apatite allows for a wide range of substitutions.
The elevated temperatures achieved under burning, or cremation, cause recrystallization of bioapatite, simplifying its analysis. The resultant material is still distinguishable from geologic apatite and can also be clearly differentiated from the materials reportedly used as fill in the urns from Tri-State. We are in the early stages of an investigation of human cremated remains. Samples of leg bones and dentin were collected from a human cremated at 1010°C for 2.5 hours for analysis. Early XRD results clearly show differences between bone apatite, dentin apatite, and geological apatite. Bone apatite shows a significant component of carbonate while dentin appears to be virtually pure apatite. We hope in the near future to assess the differences resultant from higher or lower temperature burning.