Luni (绿泥) Ore and Clay

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Overview

Luni[1] (绿泥, “green clay”) is a unique zisha ore named for its green color or hue before firing. The ore is a rare formation[2] of silty mudstone divided into many subtypes with unique properties, originally mined from the Huang Long Shan Baoshan mining site[3].

The majority of luni ore is “generic luni”, formed just below the yellow stone layer; generic luni has a larger grain size, higher sintering temperature[4], and lower firing-shrinkage, resulting in a smooth clay with high porosity.