Experimental Kangxi Monochrome "Lichen Spots" Copper Red Glaze Vase

Catalog No.: KX-LS-20-CG-01DOI: 10.5281/zenodo.16794377, 10.5281/zenodo.16876055Author: Prof. Nona Dronova, D.Sc. (ORCID: 0009-0007-4867-9074)Height: 20 cmForm: Double-gourd (shuang lian hu)Glaze: Copper red with green “lichen” inclusionsMark: Six-character Kangxi mark in underglaze cobalt blueEstimated date: c. 1690–1710Origin: Jingdezhen Imperial Kilns 1. Historical Context During the Kangxi reign (1662–1722), the Jingdezhen Imperial Kilns entered a period of intense technical innovation. While blue-and-white porcelain dominated export markets, monochrome glazes were a focus of imperial experimentation. Copper red glazes, known for their sensitivity to kiln atmosphere, had been mastered under the early Ming but remained technically challenging. Kangxi’s court sponsored a series of experimental firings aimed at reviving and refining earlier techniques, introducing new chromatic effects. Among these, the so-called “lichen spots” glaze — a deep copper red base mottled with vivid green inclusions — represented one of the most sophisticated and least common results. The green zones were not painted but emerged naturally through localized oxidation of copper during firing, producing a highly variegated, painterly surface. Such works were not produced for the open market. Pieces bearing the six-character underglaze blue Kangxi mark were exclusive to imperial orders and fired under the supervision of court-appointed kiln directors. In ordinary private or commercial workshops, imperial marks were prohibited and never applied legitimately. 2. Glaze Description The vase exhibits a semi-transparent, saturated copper red base, with two types of green inclusions: Floating zones — softly diffused edges, creating the sense of green drifting across the red surface. Abrupt zones — sharply defined “frozen” patches where green abruptly interrupts the red field. This duality suggests fluctuating kiln temperatures and shifting oxidation–reduction conditions during firing. Microscopy reveals: Red areas: microcrystalline Cu₂O network, fine craquelure. Green inclusions: glassy CuO-rich zones, with possible iron admixture; smooth surface integration. Transitions: natural and non-repetitive, with no evidence of artificial staining. Foot rim: unglazed, iron-rich clay body, natural wear; firing ring marks consistent with Jingdezhen imperial kiln supports. 3. Reconstruction of the Firing Process Fuel: Primarily hardwood charcoal, occasionally mixed with coal to achieve sustained high temperatures. Primary atmosphere: Reduction firing to produce the deep red Cu₂O. Localized oxidation: During cooling or through uneven airflow, oxygen re-entered certain zones, converting some copper oxide to the green CuO state. Temperature range: ~1250–1280 °C, with local fluctuations causing differential glaze behavior. Firing duration: Extended soak at high heat to allow glaze diffusion, followed by carefully controlled cooling. The unpredictability of copper red glazes meant that only a small proportion of experimental batches achieved this distinctive red–green variegation, making such pieces both rare and prized. 4. Cultural and Artistic Appreciation In the Kangxi court, double-gourd vases carried auspicious symbolism — the gourd (hulu) being associated with fertility, abundance, and immortality in Daoist tradition. When combined with an experimental and visually striking glaze, such a vessel would have been regarded as both a technical triumph and a bearer of good fortune. Court officials and high-ranking nobles valued these vases as displays of imperial mastery over nature and the kiln — turning volatile copper chemistry into stable beauty. Their rarity meant they were often reserved as diplomatic gifts or placed in imperial study halls (shufang) alongside other treasured monochromes. 5. Comparative Examples Smithsonian Institution, inv. no. F1916.327 — Kangxi copper red vase with similar green mottling. Shanghai Museum, cat. no. 405123 — double-gourd form with red–green “lichen” glaze, marked Kangxi. Both show comparable firing behavior and glaze chemistry, confirming this vase’s alignment with high-level imperial production. 6. Attribution and Significance Origin: Jingdezhen Imperial Kilns Period: Kangxi reign, c. 1690–1710 Type: Experimental monochrome copper red with oxidation variegation Mark: Genuine six-character underglaze blue Kangxi reign mark — indicative of imperial commission Significance: Represents one of the rarest and most technically demanding monochrome glazes achieved under Kangxi, valued for both auspicious symbolism and mastery of copper chemistry. 7. Evaluation Artistic & Historical Significance: Exceptional Rarity: Extremely rare surviving example of “lichen spots” Kangxi copper red Authenticity Probability: High (supported by microscopy, firing traces, comparative examples) License: Text CC BY 4.0, Images CC BY-SA 4.0