Chemical and structural changes in Cervus elaphus tooth enamels during fossilization (Lazaret cave): a combined IR and XRD Rietveld analysis

Tooth enamel from modern and fossil (Lazaret cave) Cervus elaphus was characterized in order to study the chemical and structural changes during fossilization. Calcium, P, Na, Mg, F, Cl, CO3, contents were measured by chemical analyses, and infrared (IR) spectroscopy was used to determine H20, OH−, P043− and C032−. Carbonate increases during fossilization and substitutes for PO43− at the B-site and for OH at the A-site. The C032−-for-PO43− substitution experiences the highest increase. Water and OH contents decrease during fossilization. These chemical changes may be traced by Rietveld structure refinement (XRD). Like human enamel, red deer enamel consists of apatite. A good positive correlation has been found between the a cell parameter and C032− contents. Refinement of atomic positions and site multiplicity allow us to describe site distortions in P043− polyhedra and along the 63 axis; these distortions are indirect probes of the substituent ions in the apatite structure.