Zisha Clay Types: What Zini, Zhuni, and Duanni Actually Mean

Every Yixing teapot is made from one of a handful of named zisha clay types, and the names get thrown around loosely in English-language shops — "zhuni" in particular is often used as a stand-in for "any reddish clay," which isn't quite right. Here's what the Chinese source material actually says these terms mean, and how the types differ in practice.

Three base categories, one shared ore body

Chinese specialist sources (zisha.com and others in the trade) group zisha into three base categories, named for the raw ore's color before firing: zini (紫泥, "purple clay"), hongni (红泥, "red clay" — the broader category that zhuni belongs to), and benshan lüni (本山绿泥, "local mountain green clay"). Everything else — duanni included — is a variation or blend built from these three.

Zini (紫泥) — the workhorse clay

Zini is the clay most Yixing pots are actually made from — by volume, it accounts for more than 60% of all zisha mined. Its parent ore, called qingni (青泥, "blue-grey clay") in its raw state, comes mainly from mid-level veins in Huanglong Mountain (黄龙山). Iron content runs 8–12%, visible in the raw ore as a blue-grey stone with flecks of mica and quartz grain in cross-section. Fired, it comes out in shades of light purple, purple-red, or deep purple depending on the specific vein and kiln temperature.

Zhuni (朱泥) — and why it's not just "red clay"

This is where English usage gets loose. Zhuni translates to "vermilion clay," and it's often used online as if it just means "the red one." More precisely: hongni is the broad category — Chinese sources describe it geologically as an argillaceous siltstone — and zhuni is a specific, finer-grained ore within that category, closer to a mudstone than a siltstone. It's sometimes classified as a subtype of hongni, sometimes treated as its own category, because the difference in particle fineness has a real effect on the fired pot.

Zhuni ore sits in shallow surface deposits, in thin, nodular seams often only tens of centimeters thick — collector sources name specific veins like Zhaozhuangshan (赵庄山) and Xiaomeiyao (小煤窑). That thinness is why it's rarer and harder to mine than zini. Raw zhuni ore is yellowish; weathering turns it orange-red, and its texture is famously fine — often described as paste-like. Iron content is the highest of the common clays, 14–18%, and that density carries through to the fired pot: zhuni teapots are denser, with smaller pores, so they conduct heat faster and hold aroma less than a zini or duanni pot does.

Duanni (段泥) — a blend, not a single ore

Duanni (also called tuanni, 团泥) isn't mined as its own material — it's a naturally co-occurring mix of zini and lüni (or other clays) found together in the same interbedded layers, mainly where the Huanglong Mountain and Qinglong Mountain (青龙山) veins meet. The raw ore comes out as a mottled, mixed-color block that has to be manually sorted and blended rather than simply dug and processed. It has the lowest iron content of the three, around 4–6%, which lines up with it also being the most porous and breathable of the common clay types — the opposite end of the spectrum from dense, low-porosity zhuni.

Benshan Lüni (本山绿泥) — green ore, yellow pot

The name is the one place this classification trips people up: benshan lüni means "green clay," describing the ore's raw, unfired color. Fired, it comes out a soft, pale yellow — not green at all. If you see a "green clay" teapot description and the photo shows a yellow or buff-colored pot, that's not a mismatch; that's exactly what benshan lüni is supposed to do.

Why the difference actually matters when you're choosing a pot

The practical takeaway, cross-checked against English-language brewing guides: porosity and heat behavior run on a spectrum, from duanni (most porous, slower to heat up, holds less heat) through zini to zhuni (least porous, heats and cools fastest, holds aroma least). A denser zhuni pot is often recommended for lighter, more aromatic teas like some oolongs, where you don't want the clay itself absorbing much fragrance; a more porous zini or duanni pot suits teas people plan to dedicate the pot to long-term, like pu-erh, where some interaction between clay and tea over years of use is part of the appeal.