Calcined Bone
Definition
Bone heated to above approximately 700°C, resulting in complete combustion of the organic component (collagen), leaving only mineral hydroxyapatite; characterised by white colour, extreme fragility, crazing, and 10 to 25 per cent dimensional shrinkage.
- Temperature threshold
- Approximately 700°C or above
- Appearance
- Chalky white color
- Key property
- Extreme fragility and brittleness
- Dimensional change
- 10 to 25 percent shrinkage
Common questions
What temperature causes bone to become calcined?+
Calcination occurs when bone is heated above approximately 700°C. At this temperature, the organic component (collagen) undergoes complete combustion, leaving only the mineral structure behind.
How can you identify calcined bone at a fire scene?+
Calcined bone appears chalky white and is extremely brittle. It fragments readily when disturbed and may show crazing, making it distinctive even in degraded fire scenes.
Does bone shrink when calcined?+
Yes. Calcined bone typically shrinks between 10 and 25 percent in its original dimensions due to the loss of water and organic material at high temperatures.
Related terms
- Burn Deposit Stratigraphy
- The layered sequence of ash, charcoal, collapsed structural elements, and debris produced by a fire, recording the temporal order of combustion events...
- Crazing
- A mosaic network of intersecting surface fissures on burned bone, produced by differential contraction of the outer bone surface relative to the...
- Delamination
- The separation of the outer table of bone from the underlying diploe or cortex in curved sheets during green-bone burning; produced by...
- Dry Bone Fracture Pattern
- Straight, longitudinal fractures running parallel to the long axis of a bone, following the Haversian structural directions; characteristic of bone burned after...
- Green Bone Fracture Pattern
- Curved transverse fractures running approximately perpendicular to the long axis of a bone, with a stepped or warped cross-sectional profile; characteristic of...
- Hydroxyapatite (HA)
- The calcium phosphate mineral [Ca10(PO4)6(OH)2] that comprises approximately 70 per cent of bone mass; survives fire at all temperature stages, sintering and...
- NFPA 921
- US National Fire Protection Association Guide for Fire and Explosion Investigations. The internationally accepted methodology Indian fire investigators and SFSL fire divisions...
- Peri-Mortem Burning
- Burning that occurred at or very close to the time of death, while green (fresh) bone still contains its organic matrix. Distinguished...
- Pope-Smith Framework
- The 2004 analytical framework distinguishing perimortem from postmortem fire exposure using fracture geometry, cross-section colour uniformity, periosteal behaviour, and anatomical integrity; explicitly...
- Pugilistic Posture
- The post-mortem flexion of the limbs and clenching of the hands caused by heat-induced differential contraction of flexor muscles. It indicates exposure...
- Seat of the Fire
- The point of ignition or the area of maximum burn intensity, identified by fire investigators from char patterns, spalling, and burning vectors....
- Shipman Colour Stages
- The five-stage colour classification (yellow-tan, brown, black, blue-grey, white) published by Patricia Shipman and colleagues in 1984, corresponding approximately to temperature ranges...
Explained in these topics
- Fire-Scene ArchaeologyBone exposed to sustained temperatures above approximately 600 degrees Celsius, resulting in complete loss of the organic (collagen) fraction.
- Thermal Trauma: Calcined Bone, Colour Stages and Heat-Induced FragmentationBone heated to above approximately 700°C, resulting in complete combustion of the organic component (collagen), leaving only mineral hydroxyapatite; characteri...