The most important part of the mill is the upper millstone (mill). It is made of one or more iron-studded pieces so it will not break. In the center on the upper side is a round hole allowing the flow of the grain. The upper stone lies snugly on the lower stone, which is carved toward the opening in order to facilitate the movement of the grain toward the rim of the stone where the friction is greater. Curved pieces of wood are placed around the millstone preventing the milled flour from collecting in large quantities around the millstone.
The millstone was usually brought from Greece. It was only at the end of the 19th and the first half oft he 20th Centuries, at the time of the Kingdom of Yugoslavia that the millstones started to be purchased from Bosnia and Serbia.