Taiwanese rock-mineral clay
Traditional 台灣岩礦泥
Taiwanese rock-mineral clay describes coarse ceramic bodies used by contemporary workshops for teaware. It is a workshop material category rather than one geological clay. Recipes, firing and surface texture vary; yankuang and commercial names such as laoyanni should be read in the context of the particular maker.
On this page
What the name does not tell you#
Taiwanese rock-mineral clay describes coarse ceramic bodies used by contemporary workshops for teaware. It is a workshop material category rather than one geological clay. Recipes, firing and surface texture vary; yankuang and commercial names such as laoyanni should be read in the context of the particular maker.
Fired colour#
- Range
- Warm ochre-brown and brick-red in oxidation; dark iron-brown, charcoal-black, or purplish-grey in reduction or wood firing, studded with white quartz and dark iron nodules1
- Depends on
- Grain size and mesh of the crushed rock, iron content of the shale, kiln atmosphere (electric oxidation, gas reduction, or wood-ash chaishao), and multiple firings
Names in the trade#
| Name | 中文 | Note | Sources |
|---|---|---|---|
| Yankuang, Yankuang hu | 岩礦泥、岩礦壺 | Studio ceramic term pioneered by Taiwanese potters in the 1980s and 1990s for stoneware bodies compounded with crushed natural rock and mineral grains. | 1 |
| Laoyanni | 老岩泥 | Commercial name popularised by Taiwanese teaware workshops (such as Taozuofang) for dark, coarse rock-mineral blends fired multiple times in oxidation and reduction. | 1 |
Firing and shrinkage#
| Temperature | Shrinkage | Note | Sources |
|---|---|---|---|
| 1230–1280 °C | — | The cited workshop account describes compounded ceramic bodies rather than a single ore. The relative amounts and identities of visible grains require a maker’s recipe or analysis of a named sample; they cannot be read from this schematic drawing. The quoted firing interval is a reported practice, not a specification for every rock-mineral clay. | 1 |
Composition and structure#
| Component | Value | Method | Sample | Sources |
|---|---|---|---|---|
| Silica (quartz), feldspar, and iron oxides | compounded stoneware clay matrix with coarse quartz, feldspar, and iron-oxide mineral grains | studio ceramic formulation described in monograph | Taiwanese yankuang teapots and boiling kettles | 1 |
Body components#
The cited workshop account describes compounded ceramic bodies rather than a single ore. The relative amounts and identities of visible grains require a maker’s recipe or analysis of a named sample; they cannot be read from this schematic drawing. The quoted firing interval is a reported practice, not a specification for every rock-mineral clay.
Where the ore is said to come from#
- Miaoli and Taiwan's Central Mountain Range (苗栗及中央山脈礦區): Weathered sedimentary rock, quartz sand, feldspar, and iron-bearing mountain shale blended with Miaoli/Nantou stoneware clay. Potters crush and screen weathered rock strata to different mesh sizes and compound them with plastic clay so the body can stand up to high stoneware temperatures without slumping.1
A named mine is the source's statement, not a guarantee for any pot.
History#
The cited 2015 monograph places these materials in contemporary Taiwanese studio teaware. Priority claims about who first formulated a body, exact quarry origins and the equivalence of trade names require independently documented workshop histories.
Known trade questions#
- Treating 'old rock clay' (老岩泥) as a single geological mine. The word lao ('old' or 'aged') refers to weathered sedimentary rock and the dark, craggy look of the fired stoneware surface, not to a single antique clay stockpile. Check: Ask the maker or brand for the firing temperature and whether the interior is unglazed or coated with a thin mineral glaze.1
Sources#
Status and editorial notes draft
Sources are listed below. Their presence does not certify every claim; source-specific interpretations and unresolved questions are identified in the text. This page has not received independent expert approval.
Exact supporting passages for the quantitative material claims and historical attributions still require checking against the cited publications.