Glaze type · Iron glazes
Chun (Jun)
Across 57 published recipes: mostly cone 10 and cone 9, fired in reduction and oxidation; Glossy, translucent.
Materials that define it
Share of recipes containing each material, and the typical amount when present. Materials link to their reference pages.
| Material | In recipes | Typical | Half of recipes |
|---|---|---|---|
| Silica | 97% | 29% | 25.5–30% |
| Whiting | 83% | 11% | 9.4–15.32% |
| Red iron oxide | 61% | 1% | 0.5–1.5% |
| Dolomite | 54% | 6.5% | 6–9.5% |
| Bentonite | 42% | 2% | 1–2% |
| Zinc oxide | 42% | 3% | 2.02–5.09% |
| Custer feldspar | 40% | 42.3% | 39.13–45% |
| Bone ash | 39% | 2% | 1.48–2.02% |
| Kaolin | 28% | 7.9% | 2–18.32% |
| Potash feldspar | 23% | 42% | 35–55.4% |
| Gerstley borate | 21% | 8.82% | 4.51–11.82% |
| Grolleg kaolin | 21% | 5.33% | 3.5–9.68% |
| EPK | 19% | 5% | 2.3–6.9% |
| Tin oxide | 18% | 2.62% | 1–4% |
Typical fired chemistry
Median oxide analysis (weight %) across the recipes that report one, with the interquartile range. Silica and alumina set the melt; the fluxes and colorants make the family.
| Oxide | Median | Half of recipes |
|---|---|---|
| SiO2 | 60.19% | 58.4–61.41% |
| Al2O3 | 9.09% | 8.14–10.07% |
| B2O3 | 3.4% | 2.37–3.79% |
| Na2O | 1.6% | 1.19–3.56% |
| K2O | 4.1% | 2–4.86% |
| CaO | 9.34% | 7.7–10.69% |
| MgO | 1.32% | 0.43–1.82% |
| ZnO | 2.93% | 1.97–4.61% |
| P2O5 | 0.49% | 0.01–0.84% |
| Fe2O3 | 0.64% | 0.16–1.16% |
Related types
Questions
- What is a Chun (Jun) glaze?
- In 57 published recipes, Chun (Jun) glazes are mostly fired to cone 10 and cone 9 in reduction and oxidation, with a Glossy, translucent result. The defining materials are Silica, Whiting, Red iron oxide, Dolomite, Bentonite.
- What cone is Chun (Jun) fired to?
- The most common cones in published recipes are cone 10 and cone 9; the full distribution is on this page. Atmosphere matters as much as cone for this family: reduction and oxidation.
- What is the typical chemistry of a Chun (Jun) glaze?
- Median fired analysis: SiO2 60.19%, Al2O3 9.09%, B2O3 3.4%, Na2O 1.6%, K2O 4.1%, CaO 9.34%. Treat these as the centre of a range, not a target — the same family spans different fluxes and cones.
Sources. Every figure is a statistic computed by Claybench over 10,859 glaze recipes compiled from publicly shared community recipe collections (snapshot 2026-02-27); no recipe is reproduced. Colour-chemistry notes are paraphrased from Linda Arbuckle's Ceramic Materials handout.
Colorant and flux notes touch on materials with handling hazards (barium, cobalt, chrome, manganese, lead in historic recipes). Read each material's page and its supplier SDS before mixing; test any food surface.
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