A.P. Middleton

Characterization and dating of recent and fossil bone by X-ray diffraction

Abstract Studies of bone chemistry are being used to reconstruct the habitat of ancient populations and it is therefore important that any post-mortem changes which may occur are as fully understood as possible. Here we address the associated problems of changes in bone crystallinity and the process of fossilization. We have examined a series of non-pathological bones ranging in age from modern to c. 2·8 Ma. Our results suggest that the older the bone the higher is its crystallinity and the sharper is its X-ray diffraction (XRD) pattern; we suggest that this phenomenon could be used as a method for estimating the degree of fossilization and could perhaps also be developed as a method for relative dating. The technique is relatively rapid and economical to apply, uses equipment that is widely available and it is practically non-destructive so that it could be used on precious bones such as those of fossil humans.

Provenancing of Egyptian limestone sculpture

Abstract A number of readily available analytical techniques have been applied to the characterization of a selection of Egyptian limestone sculptures. The results suggest that an approach involving petrographic examination in the optical and scanning electron microscopes, combined with the recovery, gravimetric estimation and mineralogical analysis by X-ray diffraction of the acid insoluble fractions of the limestones, may permit the characterization, and hence the attribution of provenance to at least three major groups of Egyptian limestone sculpture.