Exploring the Drilling Technology of Jade Tubular Ornaments in the Beinan Culture

JUAN Hsi-ting

This study investigates the drilling technology and chaîne opératoire of jade tubular ornaments (jade tubes, tubular beads, and jade rods) from the Beinan Culture (ca. 3500–2300 BP) in eastern Taiwan. While previous studies have primarily focused on jade slit rings, the perforation techniques of tubular forms remain insufficiently understood. Non-destructive compositional analysis using portable X-ray fluorescence (pXRF) indicates that nephrite is the primary raw material. This study integrates silicone moulding of drill-hole surfaces with optical microscopy (OM) and scanning electron microscopy (SEM) to examine micro-wear patterns. The results show that most specimens were perforated using bidirectional drilling, producing conical or cylindrical holes. Micro-wear features include parallel spiral striations from rotational motion, abrasion marks, and step-like detachments. These patterns suggest multiple drilling strategies involving solid stone drills and tubular drills combined with abrasive materials. By systematically applying silicone moulding and high-magnification micro-wear analysis in Taiwan, this study reconstructs the drilling sequence of tubular jade ornaments and addresses a critical gap in regional research.