合浦汉墓出土绿柱石宝石珠饰的科学分析

采用便携式拉曼光谱仪对广西合浦出土的新莽(8—23年)和东汉(25—220年)晚期的宝石珠饰进行了原位无损分析,新发现了一批在外观上极易被误认为各色水晶的绿柱石族矿物(如海蓝宝石和透绿柱石)制作而成的浅蓝色和无色透明珠饰。利用手持式显微镜对绿柱石宝石珠饰的穿孔形状、孔径大小及其内部微痕特征进行了观察分析,参考南亚和东南亚同时期石质珠饰的钻孔工艺及钻具研究成果,认为这批绿柱石珠饰采用了钻石钻头双面对钻钻孔工艺。结合南亚地区宝石资源、出土绿柱石宝石珠饰及其钻孔工艺和加工作坊等情况,认为这批绿柱石宝石珠饰是由南亚经海上丝绸之路输入的舶来品。研究结果为探讨汉代中国南方与南亚和东南亚的经济和文化交流提供了有益信息,有助于提高对古代海上丝绸之路这一贸易网络在传播珍贵物品的认识。

Scientific analysis of beryl bead ornaments unearthed from Han tombs in Hepu County

Some precious gemstone bead ornaments unearthed from Hepu County, the Guangxi Zhuang Autonomous Region, dates back to the Xinmang Period (8 AD~23 AD) and the late Eastern Han Dynasty (25 AD~220 AD). These ornaments were analyzed in situ and non-destructively using two portable Raman spectrometers. A batch of light blue and colorless transparent bead ornaments made of beryl group minerals (e.g. aquamarine and goshenite) which had been easily mistaken for colored quartz beads were successfully identified. A hand-held microscope was used to observe and analyze the shape, diameter and inner micro-wear of the drill perforations of the beryl gem beads. According to markings in the cylindrical drill holes, and their diameters, as well as the research results reported earlier for the drilling techniques and tools of stone bead ornaments from South Asia and Southeast Asia, a diamond drill was used to drill the hole from the two ends of the beads. In consideration of information obtained regarding gemstone resources, ancient beryl artifacts, and drilling techniques and workshop sites found in South Asia, we tend to think that the beryl bead ornaments were imported from South Asia via the Maritime Silk Road. This research provides valuable information for discussing the economic and cultural exchanges between southern China and South Asia and Southeast Asia during the Han Dynasty, and also improves our understanding on the ancient Maritime Silk Road trade networks for precious goods.