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.
Vitreous china and porcelain cost about the same, however, vitreous china is better at resisting spills, scrapes, or other bathroom mishaps. The high gloss enamel is very durable and creates a stain-resistant surface. Also, vitreous china has sanitary properties which are great to use in the bathroom.