This document discusses the analysis of burnt bone to determine the circumstances of burning. It outlines several techniques used including: [1] examining bone color and fracture patterns to estimate burning temperature; [2] elemental analysis to detect staining from metals; and [3] other analytical methods to assess the degree of burning. Key factors investigated are temperature, time, presence of other materials, and location of burning to better understand how and why the bones were burnt.

1. Analysis of burnt bone:
Discovering the circumstances of
burning

2. Why study burnt bone
Many Uses
Use of fire in prehistory, dietary and cooking
habits, animal sacrifices, migration and trade
in life stock, firing of cities, cannibalism, witch
executions and funerary practises
2 Questions
• What are the bones?
• What are the circumstances of burning?

3. What are the Circumstances of burning
• Temperature
• Time
• Soft tissue
• Oxidation
• Other objects (metals)
• Location

4. Analysis techniques
• Colour
• Fracture patterns
• Elemental analysis (ICP-MS/XRF)
• Other analytical techniques (XRD,FTIR,
electron microscopy)
• Use of external clues

5. Fracturing

6. Colour & Temperature
Stage Temperature range Colour description Munsell
(dominant colour)
1 20-285 °C Neutral white/ pale yellow 5Y 8/2, 10YR 8/4
2 285-525 Reddish brown, dark grey brown, neutral N 2.7 5/0
dark grey, reddish yellow 7.5YR 8/3
3 525-645 Neutral black, medium blue, some reddish 10YR 7/2
yellow
4 645-940 Predominately neutral white, with light N 9/0
blue grey and light grey N9.5/0
5 940+ Neutral white with some medium grey and N9.5/0
reddish-yellow

7. Colour & Metals
• Characteristic colour for
each metal:
e.g.
• Bronze: Green/Blue
• Iron: Red
• Zinc: Yellow

8. Problems with colour analysis
• Secondary change
• Many confounding variables

9. External clues
• The melting of another material with a known or
calculable melting point
• E.g. Glass melts at 500°C to over 2000°C depending
on the type of glass

10. Elemental analysis
Use: Examples:
• Identification of • XRF
compounds or elements • ICP-MS
• Good at detecting
staining- Metals/
minerals
• Thermal decomposition

11. Other analysis
Uses Examples
Distinguishing burnt from • XRD
unburnt • FTIR
Looking at the degree of • Electron Microscopy
burning:
• Recrystallization
• Thermal decomposition
Penetration of staining

12. XRD
NaCaPO4, CaO, MgO
30 40 50
2-Theta - Scale

13. Bibliography
Shipman, P., Foster, G. and Schoeninger, M. (1984).
Burnt Bones and teeth: an experimental study of
colour, morphology, crystal structure and shrinkage.
Journal of archaeological science, 11, pp.307-325
Harter, R.(2011). Piltdown man.
http://home.tiac.net/~cri_a/piltdown/piltdown.html
Nicholson, A.(2011). The effect of multiple burning on
bone mineral