Zini (紫泥, "purple clay") is the workhorse of Yixing: the most widely used zisha clay for teapots, and the clay most people picture when they hear "Yixing". Its names — Dicaoqing, Tianqingni, aged zini — are also some of the most loosely used in the market. This guide explains what independent sources agree on, and where they don't.
What zini is
Where it is mined. Zini comes from the Huanglongshan (Yellow Dragon Hill) area of Dingshu, Yixing. It does not form a thick seam of its own; it occurs as thin interlayers inside the thicker jiani (甲泥) clay beds.
What it is made of. Its main mineral is hydromica (illite), with kaolinite, quartz, mica and iron minerals such as hematite. Zini is relatively iron-rich, and iron is what gives it its fired colour: more iron generally means a deeper colour.
How it fires. Zini is fired at around 1,200°C (individual sources range from about 1160°C to 1250°C) and comes out purple-brown to red-brown — described as chestnut, "pig-liver" or dark liver colour. It is a relatively low-shrinkage clay that resists warping and cracking.
Why makers like it
Makers describe zini as plastic, stable and easy to control. A common traditional claim is that fired zini has a "double-pore" micro-structure that lets it "breathe", and that with long use a zini pot develops a patina (baojiang) — a deeper sheen and darker colour. These are claims from the trade, not laboratory measurements. Zini is most often recommended for pu-erh and black tea; for oolong, sources disagree on whether it suits light or heavy roasts.
"Aged" zini
The "aged" in aged zini (老紫泥) mainly refers to clay that has been stored damp for a long time before use — a process called souring (陈腐) — not to older ore. Proper souring is often described as a year or more, and long-soured clay is said to be more plastic and to take on a sheen faster, though those effects are claims. Note that a Ming-dynasty clay called 老泥 in historical texts is a different material from today's aged zini.
Dicaoqing (底槽清)
Dicaoqing comes from the bottom of the zini seam; the name refers to the bottom of the trench. The raw ore has greenish "chicken-eye" spots, the main way to recognise it. It came first from Huanglongshan Mine No. 4, and later also from Mine No. 5 and the Taixi mine. It fires to a "pig-liver" red to brown, darkening with use, and the late master Gu Jingzhou is said to have favoured it.
Two cautions. Mine No. 4 is reported to have been sealed around 1997 (one source says 2000), so "Mine No. 4 Dicaoqing" can only come from old stock. And sources disagree on how loosely the name is used — one vendor claims most pots sold as Dicaoqing are blends, a figure we could not confirm elsewhere.
Tianqingni (天青泥)
Tianqingni is the most storied of the zini names. The Ming-dynasty text Yangxian Minghu Xi by Zhou Gaoqi records that it came from Lishu and fired to a dark liver colour. The historic source was flooded or lost by the late Qing, and the original ore is essentially gone.
That raises obvious questions about what is sold as Tianqingni today. Sources disagree even on its colour — the Ming text's dark liver colour versus the blue-grey many sellers describe — and on its original location. Some sources state plainly that modern "Tianqingni" is widely faked. Treat the name as a style label, not a guarantee of historic ore.
Other names
Chijin Zini (赤金紫泥) and Zipao Yusha (紫袍玉砂) are names used in our catalogue, but we found no reliable independent description of either, so we make no claims about them.
Supply and additives
In April 2005 the Yixing city government froze zisha ore mining at Huanglongshan for three years, citing wasteful, destructive over-mining; sources differ on what happened afterwards. On additives, sources also disagree: some say adding small amounts of ceramic colouring oxides is standard practice and safe within standards, while others report dyed fakes. We record the disagreement rather than take a side.
Zini-family pots in our catalogue
We currently have 82 pots recorded under zini-family names:
| Clay name (as recorded) | Pots in stock | Capacity range |
|---|---|---|
| Aged Zini | 28 | 80–180 ml |
| Tianqingni | 17 | 65–220 ml |
| Zini | 15 | 60–220 ml |
| Chijin Zini | 10 | 120–200 ml |
| Dicaoqing | 8 | 50–140 ml |
| Zipao Yusha | 3 | 150–180 ml |
| Ash-fired Zini | 1 | 130 ml |
See them all in our Zini Clay Yixing Teapots collection.
A note on names: clay names in our catalogue are recorded as the maker or supplier gives them. We have not laboratory-tested the clays, and this guide does not certify any pot's ore.
Other clay guides: Zhuni, Zini, Duanni, Jiangponi. For an overview of all clay names, see Yixing clay types and colours; for shapes, start with the Xishi and Shipiao guides.