Longyan Kaolin – White Variety

Longyan Kaolin (龙岩高岭土) comes from Longyan City in Fujian Province, a region known for producing some of the whitest and finest kaolin clays in China. This white variety is prized for its clean fired color, fine particle size, and excellent plasticity, which makes it a direct equivalent to English Grolleg kaolin.

Kaolin’s role in glaze chemistry is twofold. First, it supplies alumina (Al₂O₃), the stabilizer that keeps glazes from running off vertical surfaces. Second, kaolin keeps dry glaze materials suspended in water, preventing them from settling into a hard pack at the bottom of the bucket.

In porcelain clay bodies, white kaolin like Longyan is essential for achieving that characteristic translucent white that defines fine Chinese and European porcelain. It is also a key ingredient in bone china, hard-paste porcelain, and bright white glazes.

The word kaolin itself comes from Gaoling (高岭), a hill near Jingdezhen in Jiangxi Province where this clay was first mined for porcelain production. The term entered Western languages in the 18th century when European traders brought back samples.

**Typical usage:** 5 to 15 percent in most glazes for suspension and alumina contribution. Up to 30 percent in porcelain clay bodies. Essential for bright, opaque white glazes.

**Western equivalents:** Grolleg Kaolin, EPK (Edgar Plastic Kaolin), Tile 6.