A structural approach in the study of bones: fossil and burnt bones at nanosize scale

We review the different factors affecting significantly
mineral structure and composition of bones.
Particularly, it is assessed that micro-nanostructural and
chemical properties of skeleton bones change drastically
during burning; the micro- and nanostructural changes
attending those phases manifest themselves, amongst others,
in observable alterations to the bones colour, morphology,
microstructure, mechanical strength and
crystallinity. Intense changes involving the structure and
chemical composition of bones also occur during the fossilization
process. Bioapatite material is contaminated by
an heavy fluorination process which, on a long-time scale
reduces sensibly the volume of the original unit cell,
mainly the a-axis of the hexagonal P63/m space group.
Moreover, the bioapatite suffers to a varying degree of
extent by phase contamination from the nearby environment,
to the point that rarely a fluorapatite single phase
may be found in fossil bones here examined. TEM images
supply precise and localized information, on apatite crystal
shape and dimension, and on different processes that occur
during thermal processes or fossilization of ancient bone,
complementary to that given by X-ray diffraction and
Attenuated Total Reflection Infrared spectroscopy. We are
presenting a synthesis of XRD, ATR-IR and TEM results
on the nanostructure of various modern, burned and
palaeontological bones