Scientific Protocol for the Authentication of Genuine Ru Yao Wares from the Northern Song Dynasty

Данный протокол предоставляет полный набор диагностических критериев, основанных на археологических находках, физико-химическом анализе и оптических исследованиях, позволяющих отличить подлинные изделия жу яо (汝窑) династии Северная Сун (ок. 1100–1127 гг. н. э.) от более поздних имитаций. Методология включает структурные, минералогические, колориметрические и оптические параметры, подтвержденные рецензируемой литературой и микроскопией высокого разрешения.

Appendix 1 : Hue Angle Diagram of Ru yao Glaze (CIELAB Parameters)

Diagram Title:
Hue Angle of Ru yao Glaze (h° ≈ 143.7° | C* ≈ 3.72)

Description:
The polar chart displays the colorimetric coordinates of a verified Ru yao glaze sample in the CIELAB color space, focusing on hue angle (h°) and chroma (C*). These two parameters are essential for identifying the optical category of Tianqing (天青釉) glaze—known for its misty, bluish-green appearance characteristic of Northern Song Ru ware.

📌 Key Parameters:

• L* (Lightness): ≈ 62.5
  Indicates a translucent, light-reflective glaze layer.

• a*: ≈ –3.0
  Negative value along the red–green axis reflects a greenish tendency.

• b*: ≈ –2.2
  Negative value along the yellow–blue axis indicates bluish tone.

• C* (Chroma): ≈ 3.72
  Low chroma, consistent with the soft, desaturated visual character of genuine Ru yao glaze.

• h° (Hue angle): ≈ 143.7°
  Located between green and blue sectors, this confirms the “grayish-blue-green” tonality typical of Tianqing glaze.

🔬 Scientific Interpretation:

This colorimetric signature (h° ≈ 143.7°) aligns closely with published spectral references for authentic Ru yao glazes from Northern Song kiln sites. The subdued chroma (C* ≈ 3.72) confirms the absence of pigmentation and points instead to optical scattering effects (Mie and Rayleigh scattering) and the influence of Fe²⁺ valence states in a reduced firing atmosphere.

References:

• Zhang Feng et al., Science and Technology of the Five Great Wares of the Song Dynasty, Science Press, 2016

• Palace Museum, Non-destructive Color Determination of Song Dynasty Guan Ware Glazes, 2023, pp. 405–413

• Dronova, N. Optical Phenomenon of Ru yao Glaze Blue Color, Zenodo (DOI: 10.5281/zenodo.16696723)

• 12. Comparative Analysis with Published Standards

  All studied samples are systematically compared against reference data on glaze color and composition, as documented in:

  • Datasets from the Palace Museum, Beijing (故宫博物院)

  • Archaeological excavation reports from the Qingliangsi kiln site (清凉寺汝窑址)

  Key Literature Sources:

  • Zhang Feng, Tao Guang, Ruan Min, et al., Science and Technology of the Five Great Wares of the Song Dynasty, Science Press, 2016, pp. 3–11.

  • Yang Yu, Feng Meng, Lin Shihua, et al., “Microstructural Analysis of Color Formation in Ru Ceramics,” Journal of Archaeological Science, 2005, Vol. 32(2): 301–310.

  • Chen Yu, Bai Yu, Wei Wu, “Structural Influence on the Optical Color Mechanism in Chinese Celadon Glazes,” International Journal of Ceramic Engineering and Science, 2020.

  • Li Zhencheng, et al., “Study of Iron Valence States in Ancient Glazes Using XPS,” Nuclear Techniques, 2008.

  • 《清凉寺汝窑2000年发掘简报》, Cultural Relics, 2001, No. 11.
    (Brief Report on the 2000 Excavation of the Qingliangsi Ru Kiln Site, in Chinese)

  • Zhang Min, et al., “Scientific Study of the Huiqing Glaze from Qingliangsi Ru Kiln,” China Cultural Heritage Science Research, 2017.

  Authored Works by Prof. Nona Dronova:

  • Dronova, Nona. The Optical Phenomenon of Blue Glaze in Ru yao Ceramics of the Northern Song Dynasty, Zenodo, 2025. DOI: 10.5281/zenodo.16696723

  • Dronova, Nona. Diagnostic Criteria for Authentic Ru yao Ceramics: Scientific Protocols and Visual Data, Zenodo, 2025. DOI: 10.5281/zenodo.16689332

  This protocol is conceived as a living scientific reference. It will continue to be updated with the latest developments in:

  • Advanced microscopy

  • Spectroscopic techniques

  • Artificial intelligence–enhanced imaging and comparative analysis.

  Supplementary Bibliography for Further Research:

  • Wood, Nigel. Chinese Glazes: Their Origins, Chemistry and Recreation, A & C Black, 1999.

  • Medley, Margaret. The Chinese Potter: A Practical History of Chinese Ceramics, Phaidon, 1989.

  • Vainker, S. J. Chinese Pottery and Porcelain: From Prehistory to the Present, British Museum Press, 1991.

  • Kerr, Rose and Wood, Nigel. Science and Civilisation in China, Volume 5 Part 12: Ceramic Technology, Cambridge University Press, 2004.

  • Rawson, Jessica. The British Museum Book of Chinese Art, Thames & Hudson, 1992.

  • Valenstein, Suzanne G. A Handbook of Chinese Ceramics, The Metropolitan Museum of Art, 1989.

  • Pierson, Stacey. Song Ceramics, Victoria and Albert Museum, 2003.

✅ Application:

This diagram may be cited in the authentication protocol under the section “Instrumental Color Diagnostics: Hue Angle and Chroma Ranges for Ru yao Glazes”. It provides a visual and quantitative benchmark for Tianqing-type glazes of high authenticity.