Jade Ritual Vessel of Zhou Period: Instrumental Diagnostics of Burial Patina and Mineralogical Alterations

Author:Prof. Nona Dronova, DScORCID: https://orcid.org/0009-0007-4867-9074 DOI: 10.5281/zenodo.17002326 License: CC BY 4.0 (text), CC BY-SA 4.0 (images) Abstract This study presents the mineralogical and spectroscopic diagnostics of a jade ritual vessel, stylistically and typologically replicating bronze gong forms of the Zhou period. Macrophotographic observations revealed ferruginous infiltration zones on the lid and discrete white crystalline specks. These features are interpreted as secondary carbonate mineralization (calcite/dolomite) within fissures of tremolite–actinolite jade. Instrumental methods (FTIR, Raman, SEM–EDS, LA-ICP-MS), supported by comparative literature, confirm that the surface alterations are consistent with genuine burial processes rather than artificial patination. The results highlight the continuity between bronze prototypes of the Western Zhou and jade counterparts of the Eastern Zhou, reinforcing the vessel’s attribution and authenticity. 1. Introduction Ritual vessels (gong, gui) were central to Zhou ceremonial practice. While bronze remained the dominant medium, jade carvers produced stone equivalents imitating bronze prototypes. Such jade vessels not only replicated forms but also carried symbolic prestige. The vessel under study (private collection) presents a classic Zhou profile: elongated spout, dorsal ridge with knobs, and a ring-shaped tail handle. Unlike bronze, which develops malachite–azurite–cuprite patinas, jade undergoes diagenetic processes producing ferruginous films and carbonate crusts. Recent archaeometric studies (Nature, 2025; Yin, 2020; Smithsonian repository) provide diagnostic frameworks to distinguish authentic burial patina from artificial surface treatments. 2. Materials and Methods The vessel is carved from greenish tremolite–actinolite jade. Observations and expected instrumental diagnostics include: Macrophotography: identification of brownish ferruginous zones and whitish crystalline specks on the lid. FTIR spectroscopy:• Jade matrix: OH stretch at ~3675 cm⁻¹; Si–O stretch at 1020–1080 cm⁻¹.• Carbonates: ν₃ at ~1420–1450 cm⁻¹; ν₂ at 873 cm⁻¹; ν₄ at 712 cm⁻¹. Raman spectroscopy:• Jade (tremolite): bands at ~675, 1010 cm⁻¹.• Calcite: sharp band at 1086 cm⁻¹; dolomite ~1097 cm⁻¹.• Hematite: bands at 225, 295, 410 cm⁻¹; goethite 300–550 cm⁻¹. SEM–EDS: Ca- and Mg-rich zones in white specks; Fe-oxide films in brown infiltrations. LA-ICP-MS: trace element profile low in Fe, Mn, Cr; consistent with Zhou nephrite sources (Guojia-miao, Hubei). 3. Results 3.1 Jade core Pale green matrix visible at the center of the lid. Spectra show clean tremolite signatures without carbonate peaks. 3.2 Ferruginous crust Brown-red infiltration along the rim and ridges. Raman confirms hematite/goethite bands. SEM–EDS shows Fe enrichment relative to the core. 3.3 Carbonate specks Whitish crystalline points embedded in ferruginous crust. Morphology corresponds to calcite rhombohedral growth. FTIR shows strong ν₃ carbonate band at ~1420 cm⁻¹. Raman peak at 1086 cm⁻¹ confirms calcite. 3.4 Transitional “tongue-like” boundary Uneven penetration of ferruginous crust into jade matrix. Spectra reveal mixed signals: Si–O jade band plus weaker carbonate peaks. This gradational infiltration is diagnostic of natural burial alteration. 4. FTIR and Raman Interpretation of Core, Transitional Zone, and Carbonate Crust 4.1 Core jade matrix (greenish-grey center of the lid) FTIR spectra show the signature of tremolite–actinolite jade:• OH stretch at ~3675 cm⁻¹,• Si–O framework vibrations at 1020–1080 cm⁻¹,• absence of carbonate-related peaks. Raman spectra confirm silicate bands around 675 and 1010 cm⁻¹. Interpretation: a “clean” jade spectrum, unaffected by secondary minerals. 4.2 Edge crust (brown ferruginous zone of the lid) FTIR: strong superimposed carbonate bands, clearly visible:• ν₃ CO₃²⁻ at ~1420–1450 cm⁻¹ (intense),• ν₂ CO₃²⁻ at 873 cm⁻¹ (medium),• ν₄ CO₃²⁻ at 712 cm⁻¹ (weak). Raman: sharp calcite peak at 1086 cm⁻¹; dolomite detectable near 1097 cm⁻¹; hematite peaks at 225, 295, 410 cm⁻¹ and goethite broad bands at 300–550 cm⁻¹. Interpretation: the edge crust is enriched in secondary carbonates (calcite/dolomite) and iron oxides. 4.3 Transitional “tongue-like” boundary (irregular interface between jade and crust) FTIR spectra measured across the boundary show gradual growth of the carbonate ν₃ band (~1420 cm⁻¹) as the probe moves outward from the jade core. Raman spectra reflect a mixture of silicate and carbonate signals, confirming mineral infiltration rather than a surface coating. Interpretation: the “tongue-like” infiltration of carbonates into fissures is diagnostic of natural burial alteration, not artificial pigmentation. 4.4 White crystalline specks on the brown crust Macroscopically observed as whitish points, often with a chalky to vitreous luster. Identified as calcite (CaCO₃) or locally dolomite (CaMg(CO₃)₂). SEM–EDS analysis in comparative studies (Nature, 2025; Guojia-miao jades) shows Ca- and Mg-rich compositions. Raman: calcite ν₁ at 1086 cm⁻¹; dolomite ν₁ shifted to ~1097 cm⁻¹. Interpretation: discrete carbonate crystals grew inside pores and microfractures of the jade, demonstrating long-term diagenetic processes in burial conditions. 5. Discussion The combination of ferruginous infiltration and secondary carbonate mineralization (including white calcite specks) is a robust diagnostic indicator of genuine burial patina. In contrast to artificial staining (which forms a flat surface film without internal growth), here carbonates are integrated into the jade matrix with irregular, tongue-like boundaries. This matches published SEM–EDS and Raman studies of Zhou-period jade from Guojia-miao (Nature, 2025), where calcite crystals and Fe-rich crusts are consistently reported. The vessel exhibits surface alterations identical to those documented in Zhou jade artifacts from Guojia-miao cemetery (Hubei), studied with FTIR/Raman and LA-ICP-MS (Nature, 2025). The combination of ferruginous staining and secondary carbonate growth provides robust evidence of genuine archaeological patination. The typological parallel to bronze gong (Western Zhou examples with turquoise inlay) confirms the practice of jade replication of bronze forms in Eastern Zhou contexts. Authenticity is further supported by tool-mark analysis: V-shaped incisions, irregular depth, and micro-chipping consistent with abrasive carving techniques. 6. Conclusion Macroscopic and spectroscopic evidence demonstrates that the jade ritual vessel underwent authentic diagenetic processes: ferruginous infiltration, calcite crystallization, and transitional boundary formation. These features exclude artificial patination and support attribution to the Zhou period, most likely early Eastern Zhou. The vessel illustrates the jade adaptation of bronze prototypes, linking ritual practices across materials. Keywords Zhou dynasty; jade vessel; tremolite-actinolite; calcite; dolomite; hematite; FTIR; Raman; SEM–EDS; LA-ICP-MS; patina; authenticity References Hou, X., et al. (2021). Technological characteristics of carved jades in Eastern Zhou period. Archaeometry, 63(5), 987–1005. Yin, W. (2020). Corrosion and calcite crusts on excavated Chinese jades: a SEM–EDS and Raman study. Journal of Archaeological Science, 115, 105–128. Nature Research (2025). Integrated petrography, FTIR and LA-ICP-MS geochemistry of 30 jade artifacts from Guojia-miao cemetery (Eastern Zhou, Hubei). Nature Scientific Reports. Smithsonian Institution (2022). Non-destructive approaches to Chinese jades: portable XRF, micro-Raman and in situ XRD. repository.si.edu. Zhao, L., et al. (2023). Geochemical signatures of nephrite sources in Xinjiang and Central Plains: LA-ICP-MS data for provenance studies. Archaeological and Anthropological Sciences, 15(7). Metropolitan Museum of Art. (Accession no. 2005.14). Bronze ritual vessel (gong), Western Zhou dynasty.