Benshan green clay
Traditional 本山綠泥
Benshan lüni is the green clay of Yixing, named for the colour of the raw ore, not of the fired pot, which is pale to deep yellow.
On this page
Understanding this material#
The Yingge Ceramics Museum says it occurs only in small amounts, is expensive and is unsuited to large pieces, so it is mostly used as a surface layer or mixed into purple and red clays; pots of pure green clay are rare. Its iron content is low, near 2 per cent, and the museum gives a shrinkage of 15 to 16 per cent.
What the name does not tell you#
A clay name is a description of material, not a certificate. It does not tell you which seam or mine the ore came from, when it was dug, how long it was aged, whether it was blended, how far the pot shrank in the kiln, or how it will change a particular tea. Because green clay is scarce and mostly used as a slip or an ingredient, the name on a pot does not tell you whether it is the whole body, a surface layer or part of a blend.
Fired colour#
- Range
- Pale yellow to yellow and deep yellow, sometimes yellow with a green cast2
- Depends on
- Firing and blend
Names in the trade#
Firing and shrinkage#
| Firing temperature | Shrinkage | Note | Sources |
|---|---|---|---|
| — | 15–16 % | Museum figure for green clay. | 1 |
Composition#
| Component | Value | Method | Sample | Sources |
|---|---|---|---|---|
| Fe2O3 | close to 2 wt% | not stated | mihuang clay and benshan lüni, as reported in a news feature | 2 |
Where the ore is said to come from#
- Dingshu, Yixing: Huanglongshan. Small reserves according to the museum; Huanglongshan duanni is said to lie between the green-clay and purple-clay layers.2
A named mine is the source's statement, not a guarantee for any pot.
Known problems#
Rarely used pure1
The museum says few works are made from pure green clay; most use it as surface decoration or in blends.
What you can check Ask whether the stated clay is the body, a surface layer or one part of a mix.
Documented practices, described with sources. None of this is said about any named seller or any single pot.
Standards#
| Standard | Clause | What it covers | Sources |
|---|---|---|---|
| GB/T 10816-2024 紫砂陶器 | record | Recommended national standard for zisha ware, issued 2024-12-31, in force 2025-07-01, replacing GB/T 10816-2008. | 4 |
| GB/T 10816-2024 紫砂陶器 | 1 (scope); foreword | Scope speaks of a fine-textured, iron-rich special clay and covers classification, technical requirements, inspection and labelling of products. The foreword says the 2008 lead and cadmium release requirements were removed from this edition. Read through a commercial English rendering of the front matter only; clauses 5 onward were not seen. | 5 |
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.