A group of archaeologists, mathematicians, chemists and physicists, has shed new light on the use of mollusc shells as personal adornments by Bronze Age people. 

The research team used amino acid racemisation analysis, light microscopy, scanning electron microscopy and Raman spectroscopy to identify the raw materials used to make beads in a complex necklace discovered at an Early Bronze Age burial site at Great Cornard in Suffolk, UK.

They discovered that Bronze Age craftspeople used species like dog whelk and tusk shells, both of which were likely to have been sourced and worked locally, to fashion tiny disc-shaped beads in the necklace. 

They analyzed the Great Cornard necklace, which had been excavated by Suffolk Archaeology.  When it was first realised that the tiny white beads had been made from shell, the question arose as to its source, whether it had been obtained locally or from a distant species. such as the Mediterranean thorny oyster (Spondylus). The Mediterranean thorny oyster is a shell of long-standing symbolic and cultural significance which is known to have been used on the Continent around the time when the Great Cornard necklace was made.

The study has shown that is not to be the case and has suggested an alternative possibility.

Dr. Beatrice Demarchi, an archaeologist at University of York, and Dr Julie Wilson, of the York Departments of Chemistry and Mathematics, says, "Dog whelks and tusk shells were likely to be available locally so these people did not have to travel far to get hold of the raw materials for their beads.
"There is evidence, from elsewhere in Britain and further afield, for the use of tusk shells at various times in the past. This may well be because they are relatively easy to work and their hollow shape is very distinctive."

Wilson added, "The statistical analysis used pattern recognition algorithms for taxonomic identification, comparing the composition of the beads with a large database of shell amino acid compositions. Although we cannot know the origin of the beads for certain, our multidisciplinary approach provides additional evidence for the identifications."

Citation: Demarchi B, O'Connor S, de Lima Ponzoni A, de Almeida Rocha Ponzoni R, Sheridan A, et al. (2014) An Integrated Approach to the Taxonomic Identification of Prehistoric Shell Ornaments. PLoS ONE 9(6): e99839. doi:10.1371/journal.pone.0099839. Source: University of York