Diamonds may be a girl’s best friend, but in ancient times, shells hung on strings and painted with ochre – an earthy pigment containing ferric oxide, typically from clay and varying from light yellow to brown or red in color – were valued by both sexes.

Ancient humans deliberately collected perforated shells to string them together as beads, according to a study just published in the open-access journal PLoS ONE by Dr. Daniella Bar-Yosef Mayer of Tel Aviv University (TAU), Dr, Iris Groman-Yaroslavski of the University of Haifa and colleagues. 

Bar-Yosef Mayer is collection manager for palaeontology at TAU’s Steinhardt Museum of Natural History who trained as a zooarchaeologist specializing in molluscs, especially shell and stone beads from archaeological sites. Groman-Yaroslavski is head of the Zinman Institute of Archeology Research Laboratory at the University of Haifa. 

They discovered that the earliest adornments in the Middle Palaeolithic Age were made possible by the invention of string and that ancient humans deliberately collected perforated shells to string them together as beads. They confirmed this by microscopic analysis and simulations.

To investigate the possibility of deliberate suspension to create strings of shell beads, the Israeli archaeology team collected the same species of perforated clamshells (Glycymeris) and simulated the potential use and wear present on the original shells: first, they systematically scraped the shells against different materials like leather, sand and stone to produce a catalogue of wear patterns and suspended the shells on strings made from wild flax to identify wear patterns specific to string suspension. They then compared these wear patterns to those of the original Qafzeh Cave shells.

The Qafzeh Cave is a prehistoric archaeological site located at the bottom of Mount Precipice in the Jezreel Valley of the Lower Galilee, south of Nazareth. Important remains of prehistoric people were discovered on the site – some of the oldest examples in the world outside of Africa of virtually anatomically modern human beings.

The shells the team found all the shells had holes (in contrast to the unperforated shells found at a nearby older site, the Misliya Cave at Mount Carmel near Haifa), suggesting that the Qafzeh Cave shells were deliberately collected and strung together as beads. 

Microscopic analysis of the five best-preserved Qafzeh Cave shells revealed traces consistent with those created in the simulated shells via contact with a string, as well as traces of shell-to-shell contact (indicating the shells hung closely together). Four of the five original shells also revealed traces of an ochre coloring treatment. 

Although it’s not possible to determine the precise symbolic meaning of the shell bead strand from Qafzeh Cave, the fact that bivalve shells are a frequent hallmark across Paleolithic sites gives a sense of their importance, said the researchers.  Additionally, the presence of a string seems to suggest that not only was shell collection important; the ability to display the shells to others also likely held significance. As one of the earliest instances of perforated objects hung on strings, the Qafzeh Cave shells also bring us closer to understanding the origins of string-making technology probably between 160,000 to 120,000 years ago.

“Modern humans collected unperforated cockle shells for symbolic purposes at 160,000 years ago or earlier, and around 120,000 they started collecting perforated shells and wearing them on a string,”  

 Bar-Yosef Mayer added. “We conclude that strings, which had many more applications, were invented within this time frame.” She also suggested that the string may have been used for many other purposes apart from shell bead suspension. “They could have been used to make traps of fishing nets, for making clothes (that would be lighter than hide), for making ropes to produce rafts, and more.”