Quern-stones (/ˈkwəːnstəʊns/) are stone tools for hand-grinding a wide variety of materials. They are used in pairs. The lower, stationary, stone is called a quern, while the upper mobile stone is called a muller or handstone.The central hole is called the hopper and a handle slot enables the handstone to be rotated. They were first used in the Neolithic era to grind cereals into flour.
