Preservation of Burned Bones: An Investigation of the Effects of Temperature and pH on Hardness

Informative Potential of Multiscale Observations in Archaeological Biominerals Down to Nanoscale

“…This is associated with a progressive denaturation of the collagen followed by degradation at ~400 ° C (Nielsen-Marsh et al 2000;Bozec and Odlyha 2011) and, consequently, to a significant drop in hardness (Kalsbeek and Richter 2006) and fragility (Stiner et al 1995). Interestingly, the macroscopic shape and sample histology is found to be relatively well conserved up to ~400 °C, albeit with traces of contamination (ashes and carbon deposition) in the Haversian porosity (Hanson and Cain 2007).…”

“…Nevertheless a series of rough indications can be derived for dense (cortical) defleshed (but still hydrated) bone samples typically collected from long bones (femur, tibia): the weight loss, mainly associated with the loss of water, increases following a quadratic trend from 5 % w at 100 °C to 30 % w at 300 °C and reaches a plateau of 35-40 % w at 400 °C (Kalsbeek and Richter 2006). This is associated with a progressive denaturation of the collagen followed by degradation at ~400 ° C (Nielsen-Marsh et al 2000;Bozec and Odlyha 2011) and, consequently, to a significant drop in hardness (Kalsbeek and Richter 2006) and fragility (Stiner et al 1995).…”

Artificially Heated Bone at Low Temperatures: A Quantitative Scanning-small-angle X-Ray Scattering Imaging Study of the Mineral Particle Size

“…Finally, a number of X-ray diff raction studies show that substantial diff erences in diff raction spectra can only be observed above 300-400 o C in the form of a progressive narrowing of the X-ray peaks indicating an increase in crystallinity and particle size (Piga et al, 2008;Rogers et al, 2002Rogers et al, , 2010Kalsbeek & Richter, 2006). Below these temperatures, the profi les only reveal minor modifi cations, which are diffi cult to interpret.…”

“…al., 2002;Hiller & Wess, 2006;Munro et al, 2007;Lebon et al, 2008Lebon et al, , 2010. Interestingly, Kalsbeek & Richter (2006) reported that the most drastic changes in mechanical properties assessed by indentation, occur in the lowest part of that range, at T ~ 50-300 o C. Th is temperature range potentially covers a wide range of socio-cultural behaviors such as cooking habits or tool manufacturing (Roberts et al, 2002). At such temperatures, the color changes can be very weak, depending on the duration of heating, which makes it impractical to distinguish from non-heated fragments in the fi eld.…”

Museum factors affecting the ageing process of organic materials: review on experimental designs and the INVENVORG project as a pilot study

“…These experiments have utilized the full range of all possible combinations of temperatures and relative humidities. The cycling of relative humidity and temperature has also been studied (Shahani et al 1989 [45] [55]). The environmental parameters that have been mostly investigated in the above-mentioned studies that play a key role in bone degradation are temperature and humidity.…”