A microkernel implements all drivers as user-space programs, and implements core features like IPC in the kernel itself. A monolithic kernel, however, implements the drivers as a part of the kernel...
Porcelain is made with kaolin clay. Kaolin is white clay that retains its white color when fired. It is fired at temperatures in excess of 1300 C and is more fully vitrified than stoneware. It is usually covered with a clear glaze, which allows the white body to show.
The purest clay is kaolin, or china clay. Called a primary clay because it is found very near its source, kaolin has few impurities and is the main ingredient used in making porcelain. Because its particle size is larger than other clays, it is not very plastic.