Calcination
Definition
Bone transformation at temperatures above 700°C: complete combustion of the organic collagen fraction, leaving only white hydroxyapatite mineral. Destroys DNA, collagen (precluding isotopic and radiocarbon analysis), and all perimortem trauma signatures except macro-structural fractures.
- Temperature threshold
- Above 700°C for bone and tooth material
- End product
- White hydroxyapatite mineral (bone) or chalky residue (wallboard)
- What it destroys
- DNA, collagen, isotopic signatures, radiocarbon dating potential, and perimortem trauma evidence except macro-structural fractures
Common questions
What happens to bone when it's calcined in a fire?+
At temperatures above 700°C, bone loses all its organic collagen material and turns into white hydroxyapatite mineral. This complete transformation destroys DNA, collagen, and microscopic evidence of trauma, leaving only the macro-structural fractures visible.
Why do fire investigators measure calcination depth on wallboard?+
Gypsum wallboard releases bound water as it heats, turning progressively white and chalky. Measuring how deep this calcination goes helps investigators map the heat exposure across a room, similar to how char depth shows fire progression.
Can you recover DNA from calcined remains?+
No. The intense heat required for calcination (typically above 700°C) destroys all DNA and collagen, making genetic analysis impossible. The white, fragile mineral residue is what remains after the organic material is completely combusted.
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Explained in these topics
- Origin and Cause: V-Patterns, Char Depth, Electrical IndicatorsThe heat-induced release of bound water from gypsum wallboard (CaSO4 . 2H2O), producing a progressively chalky, friable, and whitened zone; depth of calcinatio...
- Postmortem Dental Examination and Autopsy ProtocolThe conversion of organic tooth and bone material to calcium phosphate mineral through intense heat (typically above 700 degrees Celsius). Calcined remains are...
- Taphonomic Modifiers: Soil Chemistry, Scavenging, Fire and Water ImmersionBone transformation at temperatures above 700°C: complete combustion of the organic collagen fraction, leaving only white hydroxyapatite mineral. Destroys DNA,...