高嶺

Kaolin is a fine white clay mineral, chemically a hydrated aluminum silicate, essential to the production of porcelain. The English word derives from the French kaolin, which was borrowed from the Mandarin Gāolǐng — written 高嶺 — meaning 'high ridge' or 'high hill.' Gāolǐng is the name of a specific village and hillside near Jingdezhen in Jiangxi Province, the city that has been the center of Chinese porcelain production for over a thousand years. The clay deposits at Gaoling were first described to European audiences by the French Jesuit missionary Père François Xavier d'Entrecolles, who visited Jingdezhen in 1712 and wrote detailed letters about porcelain production — including the properties of the Gaoling clay — back to France. His letters, published in 1712 and 1722, are among the most consequential documents in the history of industrial ceramics.

The Chinese had been refining porcelain technique at Jingdezhen since at least the Song Dynasty (960–1279 CE). The Gaoling clay — fine-grained, brilliant white, with specific firing properties — was one of the two essential ingredients in true porcelain (the other being petuntse, a feldspathic stone). For centuries, the European desire to replicate Chinese porcelain — brought to Europe via the Silk Road and sea trade, prized beyond almost any other commodity — was frustrated by ignorance of these raw materials. Père d'Entrecolles's letters finally revealed the secret. European chemists began searching their own territories for equivalent clays, and kaolin deposits were eventually found in Saxony, Cornwall, and later across the globe.

The Meissen porcelain manufactory in Saxony, founded in 1710, was the first successful European hard-paste porcelain operation. It was no coincidence that Saxony had its own kaolin deposits: the chemist Johann Friedrich Böttger had discovered them while working under royal patronage (essentially under confinement, to prevent him from sharing secrets) at the court of Augustus the Strong. Kaolin entered the European mineralogical vocabulary through the French transcription of d'Entrecolles's Mandarin — Gāolǐng became kaolin — and from French spread into German Kaolin, English kaolin, and the international scientific terminology.

Today kaolin is one of the most widely used industrial minerals in the world, with applications far beyond porcelain: it is used in paper coating (to give paper its smooth surface and opacity), in rubber and plastics, in pharmaceuticals, in paint, in cosmetics, and in cable insulation. The world's largest kaolin deposits are in Georgia, USA; in Brazil; in England's Cornwall; and in Australia. None of these deposits bear any connection to the Jiangxi village that named them all. The high ridge of Gaoling still exists, still near Jingdezhen, still bearing the name that European missionaries carried westward and the entire world's ceramics industry adopted.