Journal of Spectroscopy

Journal of Spectroscopy / 2018 / Article

Research Article | Open Access

Volume 2018 |Article ID 5954146 |

Giampaolo Piga, Ana Amarante, Calil Makhoul, Eugénia Cunha, Assumpció Malgosa, Stefano Enzo, David Gonçalves, "β-Tricalcium Phosphate Interferes with the Assessment of Crystallinity in Burned Skeletal Remains", Journal of Spectroscopy, vol. 2018, Article ID 5954146, 10 pages, 2018.

β-Tricalcium Phosphate Interferes with the Assessment of Crystallinity in Burned Skeletal Remains

Academic Editor: Luciano Bachmann
Received29 Jan 2018
Accepted26 Mar 2018
Published02 May 2018


The analysis of burned remains is a highly complex process, and a better insight can be gained with advanced technologies. The main goal of this paper is to apply X-ray diffraction, partially supported by infrared attenuated total reflectance spectroscopy to determine changes in burned human bones and teeth in terms of mineral phase transformations. Samples of 36 bones and 12 teeth were heated at 1050°C and afterwards subjected to XRD and ATR-IR. The crystallinity index was calculated for every sample. A quantitative evaluation of phases was documented by using the Rietveld approach. In addition to bioapatite, the following mineralogical phases were found in the bone: β-tricalcium phosphate (β-TCP) (Ca3(PO4)2), lime (CaO), portlandite (Ca(OH)2), calcite (CaCO3), and buchwaldite (NaCaPO4). In the case of bone, besides bioapatite, only the first two mineralogical phases and magnesium oxide were present. We also observed that the formation of β-TCP affects the phosphate peaks used for CI calculation. Therefore, caution is needed when its occurrence and evaluation are carried out. This is an important warning for tracking heat-induced changes in human bone, in terms of physicochemical properties related to structure, which is expected to impact in forensic, bioanthropological, and archaeological contexts.

1. Introduction

Forensic anthropologists and bioarchaeologists are frequently confronted with the need to study and interpret burned bones. Their importance for forensic investigations and for the study of past populations is unquestionable (e.g., the 9/11 attacks) [17].

For example, burned bones from forensic settings include those of fire victims resulting from, among others, vehicle accidents, mass disasters, and house fires. In addition to accidents, in homicides, the victim’s body may be purposely burned by the perpetrator in an attempt to destroy it, thus obstructing the investigation. Indeed, the effect of high temperatures on the human body can undermine and drastically complicate the bioanthropologists’ examination. Regardless of the context, one of the key factors for the correct interpretation of the remains and the reconstruction of the incidents leading to burning is the estimation of the maximum exposure temperature [810]. Micro- and ultrastructural analyses on burned skeletal remains are crucial for obtaining a reliable estimation of maximum burning temperature [11]. While macroscopic alterations (e.g., surface colour) can be used to deduce an approximate temperature range [1215], the investigation of the micro- and ultrastructural alterations of skeletal hard tissue exposed to high temperatures has proven to be crucial to get a reliable estimation of maximum temperature [8, 9, 13, 1623]. The bone which has been thermally altered shows an increase in crystallinity, exhibiting larger crystals and lower lattice strains [8, 9, 13, 1631].

The analysis of burned remains is a highly complex process, and with new technologies available, a better insight can be gained. X-ray diffraction (XRD) often combined with Fourier-transform infrared spectroscopy attenuated total reflectance (ATR-IR) techniques is actually widely used to obtain primary material information in forensic and archaeological fields, such as the accuracy of temperature determination and the study of crystallinity [10].

The crystallinity index (CI), frequently reported in literature and quantified by ATR-IR or XRD, gives precious information about the mean changes in hydroxyapatite (HA) crystal size and microscopic structural order of tissues [3239].

Recently improved FT-IR approaches and statistical methods for the comparability of CI results have been established [40]. However, the CI does not characterize individual crystal features (e.g., size or morphology) and may fail to describe adequately the complexity and heterogeneity of heat-induced processes [41]. In fact, when bioapatite is subjected to a strong thermal treatment, we can find also a multiphase condition for the resultant product due to the transformation of a part of HA to the β-tricalcium phosphate (β-TCP) and other phases detected in different percentages among bones and teeth [23, 30, 42, 43]. The presence of β-TCP as well as the presence of other mineralogical phases due to various taphonomic effects can strongly alter the calculation of the CI and other ratios (C/P and Am/P or Am/C) to a nonnegligible level [41].

That is why a multidisciplinary approach is always advisable, possibly with the combined use of various physicochemical techniques.

The aim of this work is to demonstrate that only the combined use of XRD and ATR-IR techniques can document the various reactive transformations of the apatite phase. This is done by analyzing three experimentally burned human skeletons as well as 12 teeth at 1050°C for one hour of residence.

2. Materials and Methods

The human bone samples were taken from three different unidentified skeletons, previously inhumed at the Capuchos cemetery (Santarém, Portugal) for a minimum of three years and afterwards donated to the University of Coimbra. They have the same provenance as the unclaimed skeletons of the 21st century identified skeletal collection housed at the Laboratory of Forensic Anthropology of the University of Coimbra (Portugal) [44]. The three skeletons (CC/NI/16, CC/NI/17, and CC/NI/18) are from unidentified individuals who were nonetheless estimated to be adult females based on anthropological examinations [45].

The skeletal remains were cleaned and macerated. The most superficial region of the bones was discarded with a scalpel to avoid possible contaminated samples and only then bone powder sampling took place. Samples were then concealed in Eppendorf pellets until the XRD analysis was performed. The CC/NI/16 samples comprised the humerus, radius, ulna, femur, tibia, calcaneus, talus (see Figure 1), and ribs 9 and 10, all from the left side. Additionally, sampling of a thoracic vertebra was carried out for this skeleton. The CC/NI/17 samples comprised the right ulna, radius, tibia, and fibula as well as two thoracic and two lumbar vertebrae.

Finally, the CC/NI/18 samples were composed of the clavicle, humerus, radius, and ulna, all from the right side. Samples from one cervical, two thoracic, and one lumbar vertebra were also collected.

The 12 human molar teeth employed in this study were kindly made available from the Department of Animal Biology, Plant Biology and Ecology, Autonomous University of Barcelona (Spain).

The experimental burning of the bones from the unidentified skeletons was carried out in an electric muffle (Barracha K-3, three-phased 14A model). The bones were all subjected to gradually increasing heating from room temperature to 1050°C, which took 240 min to achieve. The muffle was then allowed to cool down to room temperature. In total, 48 samples were collected for XRD and ATR-IR analyses.

The 12 molar teeth for this experiment were heat-treated with a heating rate of 20°C/min at 1050°C for 60 minutes in air using a NEY muffle furnace. 0.5 g of each sample was ball milled in an agate jar for one minute using a SPEX Mixer/Mill model 8000, to get enough powder for the XRD and ATR-IR analyses.

2.1. XRD Analysis

A small fraction (190 mg) of powdered bones was deposited in a dedicated sample holder for XRD analysis with a circular cavity of 25 mm in diameter and 2 mm in depth. The XRD patterns were collected using the Bruker D2 PHASER instrument working at a power of 30 Kv and 10 Ma in the Bragg–Brentano vertical alignment with a Cu-Ka tube emission (). The width of divergent and antiscatter slits was 1 mm (0.61°). Primary and secondary axial Soller slits of 2.5° were also mounted with a linear detector LYNXEYE with 5° opening and a monochromatisation by Ni foil for the Kβ radiation. The powder patterns were collected in the angular range 9–140° in 2θ with a step size of 0.05°. The collection time of each pattern was pursued for 47 min.

Digitized diagrams were subjected to the analysis by the HighScore® and Match® programs which are able to locate the peak position in the 2θ reciprocal scale. The succession of peaks is compared with data from literature based on a search-match algorithm able to recognize the phase composition. The raw data were further analysed using the Rietveld approach for quantitative evaluation of phases.

The Rietveld method [46, 47] is based on an iterative best-fit strategy of experimental data. We have made use of the MAUD (Material Analysis Using Diffraction) program which simulates the pattern by incorporating the instrument function and convolving the crystallographic model based on the knowledge of chemical composition and space group with selected texture and microstructure models [48]. The program permits a selection of variables for the least squares minimization such as lattice parameters of the unit cell, atomic positions, temperature factors, occupancy of the sites, an/isotropic size, and strain broadening.

The success of the procedure is generally evaluated throughout a combination of integrated agreement factors (Rwp is the most considered) and distribution of residuals [47].

2.2. ATR Analysis

FT-IR spectra were collected in ATR mode with a Bruker Alpha Platinum-ATR interferometer in terms of absorbance versus wavenumber in the range 370–4000 cm−1, with a resolution of 4 cm−1. Each spectrum was obtained by averaging 512 interferograms. The loose powder was dispersed inside a hole cavity of spheroidal shape with its surface aligned to the plate defining it.

2.3. Crystallinity Index

The crystallinity index adopted here is the same as has been used in the majority of archaeological applications. The absorption bands at 605 and 565 cm−1 were used following baseline correction, and the heights of these absorptions peaks were summed and then divided by the height of the minimum between them [32].

3. Results

Thermally treated bones showed a very interesting variability. On a total of 48 samples burned in a muffle at 1050°C for 2 hour of residence, the following mineralogical phases were found in addition to bioapatite, namely, β-tricalcium phosphate (β–TCP) (Ca3(PO4)2), portlandite (Ca(OH)2), calcite (CaCO3), lime (CaO), and buchwaldite (NaCaPO4) (see Table 1).

Individual codeBone sampleCrystallographic phases (wt%)Bioapatite average
Crystallite size/(Å) (±10%)

CCNI16Left femur proximalBioapatite 8916027.84.73
(Ca(OH)2) 9
(CaO) 2
CCNI16Left femur distalBioapatite 9222008.95.30
(Ca(OH)2) 3
(CaO) 3
(CaCO3) 1
CCNI16Left tibia proximalBioapatite 9420278.985.17
(Ca(OH)2) 3
(CaO) 3
CCNI16Left tibia distalBioapatite 8921009.004.83
(CaO) 5
(CaCO3) 2
(Ca(OH)2) 2
(NaCaPO4) 2
CCNI16Left humerus proximalBioapatite 8620578.005.84
(Ca(OH)2) 9
(CaO) 5
CCNI16Left humerus distalBioapatite 8418008.45.85
(Ca(OH)2) 10
(CaCO3) 4
(CaO) 2
CCNI16Left ulna proximalBioapatite 8419938.025.20
(Ca(OH)2) 12
(CaO) 4
CCNI16Left ulna distalBioapatite 9418009.64.40
(CaO) 3
(CaCO3) 2
(Ca(OH)2) 1
CCNI16Left radius proximalBioapatite 8920318.65.76
(Ca(OH)2) 8
(CaO) 3
CCNI16Left radius distalBioapatite 9219709.44.91
(CaO) 3
(CaCO3) 1
CCNI16Left rib 9th anterior distalBioapatite 9819709.575.30
(CaO) 2
CCNI16Left rib 9th anterior proximalBioapatite 9618509.005.17
(CaO) 3
CCNI16Left rib 10th anterior distalBioapatite 9819009.004.74
(CaO) 1
(CaCO3) 1
CCNI16Left rib 10th anterior proximalBioapatite 9915407.84.70
(CaO) 1
CCNI16Left calcaneusBioapatite 9315949.945.63
(Ca(OH)2) 4
(CaO) 3
CCNI16Left talusBioapatite 8816299.95.00
(Ca(OH)2) 9
(CaO) 3
CCNI16Thoracic vertebraeBioapatite 9915509.335.13
(CaO) 1
CCNI16Thoracic vertebraeBioapatite 9220978.25.59
(CaO) 5
(Ca(OH)2) 3
CCNI17Right ulnaBioapatite 7118476.54.64
β-TCP 29
CCNI17Right fibulaBioapatite 6817506.64.22
β-TCP 32
CCNI17Right tibiaBioapatite 96163312.65.15
(CaO) 3
β-TCP 1
CCNI17Right radiusBioapatite 97171511.24.80
(CaO) 3
CCNI17Vertebra IBioapatite 9520629.15.10
(CaO) 2.5
β-TCP 2.5
CCNI17Vertebra IIBioapatite 98184913.94.86
(CaO) 1
β–TCP 1
CCNI17Vertebra IIIBioapatite 9120238.74.90
β-TCP 9
CCNI17Vertebra IVBioapatite 7017906.44.50
β-TCP 30
CCNI18Right clavicleBioapatite 8920259.044.87
β-TCP 11
CCNI18Right humerusBioapatite 8617668.85.60
(Ca(OH)2) 11
(CaO) 3
CCNI18Right fibulaBioapatite 9824778.055.00
(CaO) 2
CCNI18Right radiusBioapatite 97201110.35.42
β-TCP 2
(CaO) 1
CCNI18Right ulnaBioapatite 9720739.55.11
β-TCP 2
(CaO) 1
CCNI18Right tibiaBioapatite 9628009.45.02
(CaO) 4
CCNI18Vertebra IBioapatite 100200010.55.71
CCNI18Vertebra IIBioapatite 10028378.886.10
CCNI18Vertebra IIIBioapatite 10017809.55.50
CCNI18Vertebra IVBioapatite 10019079.065.43

In detail, portlandite was found in 13 specimens (weight fraction range from 2 to 12 wt%), β-TCP in 10 specimens (from 1 to 32 wt%), lime in 27 specimens (from 1 to 5 wt%), calcite in 7 specimens (from 1 to 4 wt%), and buchwaldite in 1 case (2 wt%). Only in 4 cases, bones have remained unaltered, bioapatite 100% (CC/NI/18 individual), apart from the microstructure features assessed from peak sharpening and the organic component, which is expected to be removed from the bone with the thermal treatment carried out.

The average crystallite size of the examined bioapatite varies from a lower value of 1540 Å (CC/NI/16_left rib 10 anterior proximal) to an upper value of 2837 Å (CC/NI/18_vertebra II) (mean = 1950 Å). The crystallinity index varies from a lower value of 6.10 (CC/NI/18_vertebra II) to an upper value of 4.22 (CC/NI/17_right fibula) (mean = 5.14).

An emblematic case is represented by the sample CC/NI/17_right fibula, in which the bioapatite after the heat treatment at 1050°C has partially transformed into β-TCP. The Rietveld analysis is reported in Figure 2. The experiment (data points) was fitted satisfactorily (Rwp = 6.6%) with the full line after including structure information from the mineral bioapatite (68.0 wt%) and β-TCP (32.0 wt%).

As for the teeth, only three mineralogical phases were detected in addition to bioapatite: β-TCP in 11 specimens (from 2 to 44 wt%), lime in 4 specimens (from 1 to 4 wt%), and magnesium oxide (MgO) in 4 specimens (from 1 to 3 wt%) (see Table 2).

Sample codePart of the bodyCrystallographic phases (wt%)Bioapatite average
Crystallite size/(Å) (±10%)

T1Upper left 1st molarBioapatite 55137510.453.24
β-TCP 44
(MgO) 1
T2Upper right 1st molarBioapatite 9717099.364.37
β-TCP 2
(CaO) 1
T3Lower left 3rd molarBioapatite 5714567.223.42
β-TCP 42
(MgO) 1
T4Upper left 3rd molarBioapatite 7416318.223.42
β-TCP 25
(MgO) 1
T5Upper left 2nd molarBioapatite 90183010.394.39
β-TCP 8
(CaO) 2
T6Lower right 2nd molarBioapatite 8718707.573.81
β-TCP 11
(CaO) 2
T7Upper left 1st molarBioapatite 89182210.604.29
β-TCP 8
(MgO) 3
T8Lower left 3rd molarBioapatite 78161310.073.57
β-TCP 22
T9Upper right 3rd molarBioapatite 9315808.63.70
β-TCP 7
T10Lower right 1st molarBioapatite 67174011.003.51
β-TCP 33
T11Upper left 1st molarBioapatite 9019007.63.61
β-TCP 10
T12Lower left 1st molarBioapatite 9619007.74.89
(CaO) 4

The teeth have a lower crystallinity compared to the bones; in fact, the average crystallite size varies from a lower value of 1375 Å (T1 tooth) to an upper value of 1900 Å (T11 tooth) (mean = 1702 Å). The crystallinity index varies from a lower value of 3.24 (T1 tooth) to an upper value of 4.89 (T12 tooth) (mean = 3.85).

Figure 3 represents an extreme case (T1 sample), in which the analysis of the correspondent XRD pattern has established the presence of the 44% β-TCP phase for such specimen.

Figure 4 shows the ATR-IR spectra of three burned teeth (from bottom to top: T1, T3, and T4, resp.). The spectra are reported in the wavenumber ranging from 400 to 1500 cm−1.

It is possible to recognize two main groups of bands in the range of 500–700 cm−1 and 1000–1200 cm−1, which are generally assigned to the energy mode of phosphate groups and of phosphate groups, respectively. An additional peak at about 1123 cm−1 (see Figure 3) in T1 and T3 samples as indicated by arrows is attributable to β-TCP.

Particularly, the band of the phosphates present in the ATR-IR spectrum can provide a variety of supporting information to XRD analysis, due to numerous deformations and displacements of the band shape and to the CI calculation.

In detail, Figure 5 highlights the band structure of phosphate groups in the range 500–700 cm−1 of representative samples; Figure 5(a) shows the conventional pattern of CC/NI/18_vertebra II sample in which the bioapatite phase remained unchanged after the experimental heating (HA = 100%), as far as its crystal structure is concerned; the presence and the intensity of the shoulder at about 629 cm−1 indicate the occurrence of high thermal treatments [49]. The larger average crystallite size (2837 Å) detected by XRD is coherent with the high value of CI (6.10).

Figure 5(b) documents the case (T4 tooth) in which the presence of β-TCP is rather substantial; in fact, the band begins to slightly overlap with the band of bioapatite (evidenced by the additional peaks at 456 and 555 cm−1 indicated by arrows).

Figure 5(c) represents the extreme case of T1 tooth when the presence of β-TCP is massive (44%); in fact, the band appears strongly deformed due to the complete overlap with the band of bioapatite (see the deformation of the peak at 555 cm−1 with the presence of two further peaks at 546 and 563 cm−1, resp.). In such cases, the CI calculation is problematic and the value is unusually low when compared to that of other burned bone samples.

4. Discussion and Conclusive Remarks

The occurrence of β-TCP can follow from a chemical reaction according to which Ca10(PO4)6(OH)2 is subjected at high temperature, giving 3(Ca3(PO4)2) + CaO and water vapour H2O.

If water (H2O) evaporates completely, we observe the presence of CaO; alternatively, incomplete evaporation develops into Ca(OH)2. It depends on the speed of cooling after the burning process.

Recent studies [50] have attempted to clarify the transformation of a Ca-deficient synthetic apatite to β-TCP. Upon heating (calcining) to 710 ± 740°C, the Ca-deficient apatite will transform to the low-temperature polymorph of β-TCP, with the loss of water as described by where CaO is missing with respect to the 2(Ca5(PO4)3(OH)) conventional formula recognized for bioapatite.

NaCaPO4 and MgO are also observed in very small quantities probably as a consequence of impurities in the starting bone material.

The presence of β-TCP phase from bones appears to be sporadic and seems to occur only at high temperatures, around 1100°C [43]. Conversely, in our previous work, we observed a more systematic occurrence of β-TCP in teeth specimens at temperatures as low as 750°C [41].

The reason why β-TCP appears in teeth at a relatively moderate temperature in comparison to bones is still obscure; it may be related to the fact that bones and teeth have different compositions and histologies, and further studies need to be addressed by acquiring information about chemical species and following the crystal structure parameters.

Our results demonstrate that the use of the CI for bioanthropological inferences such as those related to temperature estimation [8, 9, 35, 39] and to the determination of bone quality and preservation [32, 33] is not a straightforward procedure. Since the generation of β-TCP can affect the phosphate peaks located at the wavelength of interest for CI calculation, one should be especially careful whenever such peaks present anomalous shapes.

This paper alerts to this problem since implications for fields that incorporate bone analyses may be major.

Conflicts of Interest

The authors declare that there is no conflict of interests regarding the publication of this paper.


This work was partially supported by the Autonomous Region of Sardinia (LR3/2008-R.Cervelli and S. Politiche), with the research project titled “Archaeometric and Physico-Chemical Investigation Using a Multi-Technique Approach on Archaeological, Anthropological and Paleontological Materials from the Mediterranean area and Sardinia.”


  1. M. Bohnert, T. Rost, and S. Pollak, “The degree of destruction of human bodies in relation to the duration of the fire,” Forensic Science International, vol. 95, no. 1, pp. 11–21, 1998. View at: Publisher Site | Google Scholar
  2. S. Beckett, K. D. Rogers, and J. D. Clement, “Inter-species variation in bone mineral behavior upon heating,” Journal of Forensic Sciences, vol. 56, no. 3, pp. 571–579, 2011. View at: Publisher Site | Google Scholar
  3. J. I. McKinley, “The analysis of cremated bone,” in Human Osteology: in Archaeology and Forensic Science, M. Cox and S. Mays, Eds., Greenwich Medical Media Ltd, London, GB, 2000. View at: Google Scholar
  4. T. J. U. Thompson, “Recent advances in the study of burned bone and their implications for forensic anthropology,” Forensic Science International, vol. 146, pp. S203–S205, 2004. View at: Publisher Site | Google Scholar
  5. D. H. Ubelaker, “The forensic evaluation of burned skeletal remains: a synthesis,” Forensic Science International, vol. 183, no. 1-3, pp. 1–5, 2008. View at: Publisher Site | Google Scholar
  6. D. Gonçalves, T. J. U. Thompson, and E. Cunha, “Implications of heat-induced changes in bone on the interpretation of funerary behaviour and practice,” Journal of Archaeological Science, vol. 38, no. 6, pp. 1308–1313, 2011. View at: Publisher Site | Google Scholar
  7. D. Gonçalves, T. J. U. Thompson, and E. Cunha, “Estimation of the pre-burning condition of human remains in forensic contexts,” International Journal of Legal Medicine., vol. 129, no. 5, pp. 1137–1143, 2014. View at: Publisher Site | Google Scholar
  8. G. Piga, A. Malgosa, T. J. U. Thompson, and S. Enzo, “A new calibration of the XRD technique for the study of archaeological burned human remains,” Journal of Archaeological Science, vol. 35, no. 8, pp. 2171–2178, 2008. View at: Publisher Site | Google Scholar
  9. G. Piga, A. Malgosa, T. J. U. Thompson, and S. Enzo, “The potential of X-ray diffraction in the analysis of burned remains from forensic contexts,” Journal of Forensic Sciences, vol. 54, no. 3, pp. 534–539, 2009. View at: Publisher Site | Google Scholar
  10. S. T. D. Ellingham, T. J. U. Thompson, M. Islam, and G. Taylor, “Estimating temperature exposure of burnt bone — a methodological review,” Science & Justice, vol. 55, no. 3, pp. 181–188, 2015. View at: Publisher Site | Google Scholar
  11. T. J. U. Thompson, “Heat-induced dimensional changes in bone and their consequences for forensic anthropology,” Journal of Forensic Sciences, vol. 50, no. 5, pp. 1–8, 2005. View at: Publisher Site | Google Scholar
  12. P. Shipman, G. Foster, and M. Schoeninger, “Burnt bones and teeth: an experimental study of color, morphology, crystal structure and shrinkage,” Journal of Archaeological Science, vol. 11, no. 4, pp. 307–325, 1984. View at: Publisher Site | Google Scholar
  13. J. Buikstra and M. Swegle, “Bone modification due to burning: experimental evidence,” in Bone Modification, R. Bonnichsen and M. H. Sorg, Eds., pp. 247–258, Center for the Study of the First Americans, Orono, ME, USA, 1984. View at: Google Scholar
  14. L. Bennett, “Thermal alteration of buried bone,” Journal of Archaeological Science, vol. 26, no. 1, pp. 1–8, 1999. View at: Publisher Site | Google Scholar
  15. J. J. Schultz, M. W. Warren, and J. S. Krigbaum, “Analysis of human cremains: gross and chemical methods,” in The Analysis of Burned Human Remains, C. W. Schmidt and S. A. Symes, Eds., pp. 75–94, Academic Press, London, 2008. View at: Publisher Site | Google Scholar
  16. J. L. Holden, J. G. Clement, and P. P. Phakey, “Age and temperature related changes to the ultrastructure and composition of human bone mineral,” Journal of Bone and Mineral Research, vol. 10, no. 9, pp. 1400–1409, 1995. View at: Publisher Site | Google Scholar
  17. T. Nakano, A. Tokumura, and Y. Umakoshi, “Variation in crystallinity of hydroxyapatite and the related calcium phosphates by mechanical grinding and subsequent heat treatment,” Metallugical and Materials Transactions A, vol. 33, no. 3, pp. 521–528, 2002. View at: Publisher Site | Google Scholar
  18. K. D. Rogers and P. Daniels, “An X-ray diffraction study of the effects of heat treatment on bone mineral microstructure,” Biomaterials, vol. 23, no. 12, pp. 2577–2585, 2002. View at: Publisher Site | Google Scholar
  19. J. Hiller, T. J. U. Thompson, M. P. Evison, A. T. Chamberlain, and T. J. Wess, “Bone mineral change during experimental heating: an X-ray scattering investigation,” Biomaterials, vol. 24, no. 28, pp. 5091–5097, 2003. View at: Publisher Site | Google Scholar
  20. S. Enzo, M. Bazzoni, V. Mazzarello, G. Piga, P. Bandiera, and P. Melis, “A study by thermal treatment and X-ray powder diffraction on burnt fragmented bones from tombs II, IV and IX belonging to the hypogeic necropolis of “Sa Figu” near Ittiri, Sassari (Sardinia, Italy),” Journal of Archaeological Science, vol. 34, no. 10, pp. 1731–1737, 2007. View at: Publisher Site | Google Scholar
  21. M. Figueiredo, A. Fernando, G. Martins, J. Freitas, F. Judas, and H. Figueiredo, “Effect of the calcination temperature on the composition and microstructure of hydroxyapatite derived from human and animal bone,” Ceramics International, vol. 36, no. 8, pp. 2383–2393, 2010. View at: Publisher Site | Google Scholar
  22. S. Galeano and M. L. García-Lorenzo, “Bone mineral change during experimental calcination: an X-ray diffraction study,” Journal of Forensic Sciences, vol. 59, no. 6, pp. 1602–1606, 2014. View at: Publisher Site | Google Scholar
  23. M. A. Sandholzer, T. Sui, A. M. Korsunsky, A. D. Walmsley, P. J. Lumley, and G. Landini, “X-ray scattering evaluation of ultrastructural changes in human dental tissues with thermal treatment,” Journal of Forensic Sciences, vol. 59, no. 3, pp. 769–774, 2014. View at: Publisher Site | Google Scholar
  24. R. E. Taylor, P. E. Hare, and T. D. White, “Geochemical criteria for thermal alteration of bone,” Journal of Archaeological Science, vol. 22, no. 1, pp. 115–119, 1995. View at: Publisher Site | Google Scholar
  25. S. Chakraborty, S. Bag, S. Pal, and A. K. Mukherjee, “Structural and microstructural characterization of bioapatites and synthetic hydroxyapatite using X-ray powder diffraction and Fourier transform infrared techniques,” Journal of Applied Crystallography, vol. 39, no. 3, pp. 385–390, 2006. View at: Publisher Site | Google Scholar
  26. S. E. Etok, E. Valsami-Jones, T. J. Wess et al., “Structural and chemical changes of thermally treated bone apatite,” Journal of Materials Science, vol. 42, no. 23, pp. 9807–9816, 2007. View at: Publisher Site | Google Scholar
  27. L. E. Munro, F. J. Longstaffe, and C. D. White, “Burning and boiling of modern deer bone: effects on crystallinity and oxygen isotope composition of bioapatite phosphate,” Palaeogeography Palaeoclimatology Palaeoecology, vol. 249, no. 1-2, pp. 90–102, 2007. View at: Publisher Site | Google Scholar
  28. G. Piga, A. Malgosa, V. Mazzarello, P. Bandiera, P. Melis, and S. Enzo, “Anthropological and physico-chemical investigation on the burnt remains of tomb IX in the “Sa Figu” hypogeal necropolis (Sassari-Italy)-Early Bronze Age,” International Journal of Osteoarcheology, vol. 18, no. 2, pp. 167–177, 2008. View at: Publisher Site | Google Scholar
  29. K. Rogers, S. Beckett, S. Kuhn, A. Chamberlain, and J. Clement, “Contrasting the crystallinity indicators of heated and diagenetically altered bone mineral,” Palaeogeography Palaeoclimatology Palaeoecology, vol. 296, no. 1-2, pp. 125–129, 2010. View at: Publisher Site | Google Scholar
  30. T. Sui, M. A. Sandholzer, A. J. G. Lunt et al., “In situ X-ray scattering evaluation of heat-induced ultrastructural changes in dental tissues and synthetic hydroxyapatite,” Journal of the Royal Society Interface, vol. 11, no. 95, article 20130928, 2014. View at: Publisher Site | Google Scholar
  31. G. Piga, M. D. Baró, I. Golvano Escobal et al., “A structural approach in the study of bones: fossil and burnt bones at nanosize scale,” Applied Physics A, vol. 122, no. 12, article 1031, 2016. View at: Publisher Site | Google Scholar
  32. S. Weiner and O. Bar-Yosef, “States of preservation of bones from prehistoric sites in the Near East: a survey,” Journal of Archaeological Science, vol. 17, no. 2, pp. 187–196, 1990. View at: Publisher Site | Google Scholar
  33. T. A. Surovell and M. C. Stiner, “Standardizing infra-red measures of bone mineral crystallinity: an experimental approach,” Journal of Archaeological Science, vol. 28, no. 6, pp. 633–642, 2001. View at: Publisher Site | Google Scholar
  34. M. Lebon, I. Reiche, F. Fröhlich, J.-J. Bahain, and C. Falguères, “Characterization of archaeological burnt bones: contribution of a new analytical protocol based on derivative FTIR spectroscopy and curve fitting of the ν1ν3 PO4 domain,” Analytical and Bioanalytical Chemistry, vol. 392, no. 7-8, pp. 1479–1488, 2008. View at: Publisher Site | Google Scholar
  35. T. J. U. Thompson, M. Gauthier, and M. Islam, “The application of a new method of Fourier transform infrared spectroscopy to the analysis of burned bone,” Journal of Archaeological Science, vol. 36, no. 3, pp. 910–914, 2009. View at: Publisher Site | Google Scholar
  36. M. Lebon, I. Reiche, J.-J. Bahain et al., “New parameters for the characterization of diagenetic alterations and heat-induced changes of fossil bone mineral using Fourier transform infrared spectrometry,” Journal of Archaeological Science, vol. 37, no. 9, pp. 2265–2276, 2010. View at: Publisher Site | Google Scholar
  37. K. E. Squires, T. J. U. Thompson, M. Islam, and A. Chamberlain, “The application of histomorphometry and Fourier transform infrared spectroscopy to the analysis of early Anglo-Saxon burned bone,” Journal of Archaeological Science, vol. 38, no. 9, pp. 2399–2409, 2011. View at: Publisher Site | Google Scholar
  38. T. J. U. Thompson, M. Islam, K. Piduru, and A. Marcel, “An investigation into the internal and external variables acting on crystallinity index using Fourier transform infrared spectroscopy on unaltered and burned bone,” Palaeogeography Palaeoclimatology Palaeoecology, vol. 299, no. 1-2, pp. 168–174, 2011. View at: Publisher Site | Google Scholar
  39. S. T. D. Ellingham, T. J. U. Thompson, and M. Islam, “The effect of soft tissue on temperature estimation from burnt bone using Fourier transform infrared spectroscopy,” Journal of Forensic Sciences, vol. 61, no. 1, pp. 153–159, 2015. View at: Publisher Site | Google Scholar
  40. T. J. U. Thompson, M. Islam, and M. Bonniere, “A new statistical approach for determining the crystallinity of heat-altered bone mineral from FTIR spectra,” Journal of Archaeological Science, vol. 40, no. 1, pp. 416–422, 2013. View at: Publisher Site | Google Scholar
  41. G. Piga, D. Gonçalves, T. J. U. Thompson, A. Brunetti, A. Malgosa, and S. Enzo, “Understanding the crystallinity indices behavior of burned bones and teeth by ATR-IR and XRD in the presence of bioapatite mixed with other phosphate and carbonate phases,” International Journal of Spectroscopy, vol. 2016, Article ID 4810149, 9 pages, 2016. View at: Publisher Site | Google Scholar
  42. L. D. Mkukuma, J. M. S. Skakle, I. R. Gibson, C. T. Imrie, R. M. Aspden, and D. W. L. Hukins, “Effect of the proportion of organic material in bone on thermal decomposition of bone mineral: an investigation of a variety of bones from different species using thermogravimetric analysis coupled to mass spectrometry, high-temperature X-ray diffraction, and Fourier transform infrared spectroscopy,” Calcified Tissue International, vol. 75, no. 4, pp. 321–328, 2004. View at: Publisher Site | Google Scholar
  43. G. Piga, G. Solinas, T. J. U. Thompson, A. Brunetti, A. Malgosa, and S. Enzo, “Is X-ray diffraction able to distinguish between animal and human bones?” Journal of Archaeological Science, vol. 40, no. 1, pp. 778–785, 2013. View at: Publisher Site | Google Scholar
  44. M. T. Ferreira, R. Vicente, D. Navega, D. Gonçalves, F. Curate, and E. Cunha, “A new forensic collection housed at the University of Coimbra, Portugal: the 21st century identified skeletal collection,” Forensic Science International, vol. 245, pp. 202.e1–202.e5, 2014. View at: Publisher Site | Google Scholar
  45. P. Murail, J. Bruzek, F. Houët, and E. Cunha, “DSP: a tool for probabilistic sex diagnosis using worldwide variability in hip-bone measurements,” Paru dans Bulletins et mémoires de la Société d'Anthropologie de Paris, vol. 17, no. 3-4, 2005. View at: Google Scholar
  46. H. M. Rietveld, “Line profiles of neutron powder-diffraction peaks for structure refinement,” Acta Crystallographica, vol. 22, no. 1, pp. 151-152, 1967. View at: Publisher Site | Google Scholar
  47. A. Young, The Rietveld Method, IUCr, Oxford Science Publications, Oxford, 1993.
  48. L. Lutterotti, “Total pattern fitting for the combined size-strain-stress-texture determination in thin film diffraction,” Nuclear Instruments and Methods in Physics Research Section B, vol. 268, no. 3-4, pp. 334–340, 2010. View at: Publisher Site | Google Scholar
  49. G. Piga, M. Guirguis, P. Bartoloni, A. Malgosa, and S. Enzo, “A funerary rite study of the Phoenician–Punic necropolis of Mount Sirai (Sardinia, Italy),” International Journal of Osteoarchaeology, vol. 20, pp. 144–157, 2010. View at: Publisher Site | Google Scholar
  50. I. R. Gibson, I. Rehman, S. M. Best, and W. Bonfield, “Characterization of the transformation from calcium-deficient apatite to β–tricalciumphosphate,” Journal of Materials Science: Materials in Medicine, vol. 12, pp. 799–804, 2000. View at: Publisher Site | Google Scholar

Copyright © 2018 Giampaolo Piga et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

More related articles

997 Views | 400 Downloads | 5 Citations
 PDF Download Citation Citation
 Download other formatsMore
 Order printed copiesOrder

Related articles

We are committed to sharing findings related to COVID-19 as quickly as possible. We will be providing unlimited waivers of publication charges for accepted research articles as well as case reports and case series related to COVID-19. Review articles are excluded from this waiver policy. Sign up here as a reviewer to help fast-track new submissions.