Implementing lead isotopes for tracing the source of copper-coated steatite beads from the south Levantine Chalcolithic period

Research on the use of copper during the Late Chalcolithic (LC), the first metal-bearing era in the southern Levant, has hitherto neglected an important component – copper-coated steatite beads, uncovered in multiple LC sites and contexts. In this study, we conducted a multifaceted study of green and off-white beads found in 1960 in the Cave of Skulls (Judean Desert, Israel), where the largest LC bead collection known to date was uncovered. For the first time, the green coating was extracted from the beads and analyzed separately. Combining scanning electron microscope and lead isotope analysis (LIA), the study shows that all beads were made of fired steatite, and some were coated with a copper mineral. The LIA results could not trace the origin of the steatite, but point to the either Faynan or Amram Valley in the Arabah Valley as likely sources of the Cu minerals. It is therefore suggested that the green beads were manufactured in two separate processes – one for the production of the steatite beads, and the other for the addition of the copper coating, each taking place in a different location. Tracing the Cu-mineral coating process to the Arabah sheds further light on economic connections between south Levantine sedentary and mobile groups during the late fifth millennium BCE.