Attribution of a Chinese Vase with Purple Enamel from the Qianlong Period (ca. 1770–1790)

Author: Prof. Nona Dronova, D.Sc. (Tech.)
ORCID: 0009-0007-4867-9074
DOI 10.5281/zenodo.16904076

📌 Abstract

This article is devoted to the attribution of a rare porcelain vase with purple overglaze enamel and famille-rose decoration, manufactured at the imperial kilns of Jingdezhen during the reign of the Qianlong Emperor. Both macroscopic and microscopic analyses were carried out; the iconographic program, enamel structure, and diagnostic features confirming authenticity and imperial origin of the piece are described. The study refers to comparative data on Chinese enamels of the eighteenth century (Colomban, Norris, Li, Dronova, and others).

Keywords: Qianlong, famille-rose, purple enamel, overglaze pigments, microscopy, Chinese porcelain, imperial kilns.

🖼️ Object Description

• Provenance: China, Jingdezhen, imperial workshops

• Date: Qianlong period, ca. 1770–1790

• Material: white porcelain, famille-rose enamels, purple overglaze enamel, turquoise glaze, underglaze cobalt

• Dimensions: height 26 cm

• Form: globular body with relief petal-shaped foot and slightly flaring mouth

• Mark: six-character seal mark in underglaze cobalt blue 「大清乾隆年製」 on turquoise glaze

The main ground is a dense purple enamel, varying from cool lilac to warmer rose-violet tones. The famille-rose decoration covers the purple background with lotus scrolls, blossoms, red bats, ruyi-head border and lotus lappets.

🎨 Decoration and Iconography

1. Lotus scroll (liántángcǎo) — symbol of purity and continuity.

2. Red bats (fú) — rebus for “happiness has arrived” (dao/fu pun).

3. Borders: ruyi heads (“as you wish”) and lotus petal lappets.

4. “Brocade-like” background (jin-di) — a woven-like ornamental ground, typical of the Qianlong court style.

📚 Comparable examples: Palace Museum, Beijing; Colomban (2020); Norris (2020).

🔬 Microscopic Analysis

1. Purple enamel

• Under magnification it shows a “snowy” texture with fine bubbles and granular inclusions.

• The color results from gold nanoparticles in a lead-silicate matrix, with additions of Mn/Co/Fe.

• This confirms the rare “imperial” recipe for lilac-purple tones during the Qianlong period.

2. Pink famille-rose enamel

• A granular, sugary texture with tiny bubbles.

• Colloidal gold dispersed in a Pb-Si glass matrix, with Pb-As opacifiers.

• Produces the characteristic cranberry-pink tone, unattainable in later imitations using organic dyes.

3. Brown contour lines

• Grainy structure of Mn-based pigment, applied with a brush.

• Distinct from modern copies where lines appear flat and uniform.

4. Stratification and firing sequence

• Clear technological layering: purple ground → pink/green decoration → brown Mn outlines.

• Indicates at least 4–5 firings, consistent with imperial famille-rose technology.

5. Turquoise glaze and mark

• Underglaze cobalt absorbed into the turquoise glaze without spreading.

• Turquoise glaze shows glossy waves and microbubbles characteristic of 18th-century firing.

⚙️ Reconstruction of Firing Technology

1. Primary firing of porcelain body at ~1300 °C.

2. Turquoise glaze with cobalt mark, fired at ~1260 °C.

3. Purple enamel (Pb-Si, Au + Mn/Co), fired at ~800 °C.

4. Famille-rose decoration (pink, green), fired at ~760–780 °C.

5. Brown contour in manganese pigment, separate firing.

6. Possible gilding, low-temperature firing at ~620 °C.

✅ Diagnostic Features of Authenticity (based on microphotos)

1. Grainy Mn contour lines → brush application, traditional pigment.

2. “Snowy” structure of purple enamel → Au nanoparticles in Pb-Si matrix.

3. Layered enamels with meniscus edges → multiple firings, not single industrial glaze.

4. Microbubbles and devitrification “ice-crystals” → low-temperature historical enamels.

5. Absence of decal transfer grid or cold retouching → excludes later factory imitations.

🏛️ Conclusion

All macroscopic and microscopic features — the rare purple enamel, famille-rose stratigraphy, manganese contours, multi-step firing technology, and the cobalt mark — confirm the attribution:
The vase was produced at the imperial kilns of Jingdezhen during the Qianlong period (ca. 1770–1790), as part of courtly experiments with rare colors.

📚 References

• Colomban, P. et al. Investigation of the Pigments and Glassy Matrix of Painted Enamelled Qing Dynasty Chinese Porcelains. Heritage 3 (2020).

• Colomban, P. Distinguishing Genuine Imperial Qing Dynasty Porcelain by On-Site Non-Destructive pXRF Mapping. Materials 15 (2022).

• Norris, D. The Composition and Technology of Polychrome Enamels on Chinese Ruby-Backed Plates. DPhil Thesis, University of Oxford (2020).

• Li, Y. et al. Study of Arsenic in Famille Rose Porcelain from the Imperial Palace of Qing Dynasty. Ceramics International 44 (2018).

• The Quest for the Western Colors in China Under the Qing Emperors. Journal18 (2024).

• Dronova, N. D. What You Need to Know About Antique Chinese Porcelain [Что надо знать о старинном китайском фарфоре]. Moscow: OOO “Tipografiya KEM”, 2016, p. 215. DOI: 10.5281/zenodo.16794377. ISBN 978-5-9908782-6-6.