Crafting illusions: Human-made composite coating used to simulate amber beads in prehistoric Iberia.

The discovery of a set of beads, comprising both Sicilian amber and resin-coated beads in the Middle Bronze Age burial site of Cova del Gegant (Sitges, Barcelona, Spain), has sparked inquiries into whether the coating was intended for imitation or counterfeiting of amber. We assert that human-made materials, such as bead coatings, are intentionally conceived, designed, and crafted to fulfill specific functions. Thus, for an object to effectively fulfill its intended purpose, it must meet particular performance criteria influenced by situational factors. This paper aims to construct an empirically grounded narrative elucidating the development and function of resin-coated bead technology. Our methodology includes a comprehensive quantitative analysis of the coating and beads, an exploration of the interplay between technical choices and situational factors, and an investigation into whether the simulation of sensory performance characteristics played a pivotal role in the concept and design of resin-coated beads. Additionally, we synthesize data to unveil broader patterns related to the crafting and utilization of resin-coated and amber beads across time and space. We have documented resin-coated beads in the Iberian Peninsula from the Neolithic period (5th to 3rd millennia BCE) until at least the Middle Bronze Age (first half of the 2nd millennium BCE), where they coexisted with amber beads. Analysis employing ATR-FTIR and μ-CT imaging has revealed a composite coating comprising pine resin, beeswax, and carotene, adhered to shell beads with bone glue. This composite material represents the earliest known development in human history, unique to the Iberian Peninsula and without parallel in Prehistoric Europe. Our examination of the performance characteristics and functional roles of resin-coated beads suggests their potential as substitutes for amber beads, particularly in regions where amber was scarce or inaccessible. Despite being crafted from commonplace materials, these coated beads exhibit intentional design choices likely aimed at simulating the visual performance characteristics of amber. This deliberate effort, alongside their widespread distribution across time and space, indicates that composite-coated beads held symbolic and social significance akin to amber beads. • Our study quantitatively examines the development of coated beads in prehistoric Iberia, offering a thorough hypothesis of their past function and use. • Our study uses ATR-FTIR and μ-CT scans for a comprehensive analysis of these artifacts' composition and structure, appealing to a broad audience. • Our findings show the oldest evidence of humanmade composite material, bonded to a shell by bone glue, indicating advanced prehistoric design. • We uncover how these beads were designed to visually mimic amber, aiming for a specific color and aging process. • Our study highlights the social and symbolic significance of amber-like beads in high-status adornment, analyzing factors driving this technology. • The Tagus estuary concentration of these beads suggests a nuanced understanding of genuine amber scarcity and the need for innovative adornment technology. [ABSTRACT FROM AUTHOR]