Characteristics and Provenance of Tremolite Jade Artifacts from the Fangjiagang Cemetery of the Eastern Zhou Dynasty, Hubei, China

Hubei Province is a significant center for cultural and trade exchange in Central China. However, since no nephrite deposit has been discovered in Hubei, nephrite artifacts excavated within its jurisdiction must have been obtained from other regions. Tracing their provenance can contribute to our understanding of the trade exchange between ancient Hubei and other regions. In this study, the appearance, spectroscopy, and chemical compositions of nephrite artifacts excavated from the Fangjiagang Cemetery of the Eastern Zhou Dynasty, Hubei Province, were systematically studied, and their provenance was discussed. The characteristics of a weathered layer of raw nephrite material retained in one of the jade artifacts (M22:5) indicate it should be made from the placer nephrite of Hetian, Xinjiang. Infrared and Raman spectroscopy confirms that both the whitened and unwhitened areas in the samples are composed of tremolite, indicating that the whitening mechanism should be attributed to the etched structures caused by weathering rather than a change in the major mineral composition caused by high temperature. When no obvious appearance-based characteristics remain, chemical compositions become a crucial tool for discussing the provenance of jade artifacts. The chondrite-normalized rare earth element patterns for the samples suggest that their formation is associated with granite intrusion, implying that the placer nephrite of Hetian, Xinjiang; Xiuyan nephrite, Liaoning; Golmud nephrite, Qinghai; Xiaomeiling nephrite, Jiangsu; Vitim nephrite, Russia; and Chuncheon nephrite, South Korea, are potential sources. However, the trace element spider diagrams for the samples show a better match with those of the placer nephrite of Hetian. The placer nephrite of Hetian was used in Fangjiagang Cemetery, indicating that the trade exchange between the Eastern Zhou dynasty and the Hetian area had already been established.