What is "metakaolin"

n. A dehydroxylated form of the clay mineral kaolinite.

Metakaolin is a dehydroxylated form of the clay mineral kaolinite.

Stone that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of porcelain. The particle size of metakaolin is smaller than cement particles, but not as fine as silica fume.