Metakaolin is a fine, white powder made by heating kaolin, a type of clay, to a specific temperature. This process, known as calcination, removes water and transforms the clay into a more reactive form. Metakaolin is commonly used as a supplementary cementitious material in concrete and other construction applications. Due to its pozzolanic properties, metakaolin can enhance the strength and durability of concrete while reducing the amount of cement needed. This not only improves the environmental impact of construction but also helps in achieving better performance in various structural applications.