Weathering causes spiral fractures, splintered and straight patterns, exposure to air causes cracking and flaking. Bones exposed to bright sunlight for some time are rapidly bleached which aids in the destruction of the organic matrix and may result in complete break-up of bone almost to a white powder.



Weathering of a horse femur shows the lengthwise
fracture and flaking of the bone.


Further weathering stages of horse femur
showing extensive exfoliation and deep
cracks.