What are millstones used for?

Millstones are stones used in gristmills, for grinding wheat or other grains.

Millstones come in pairs. The base or bedstone is stationary. Above the bedstone is the turning runner stone which actually does the grinding. The runner stone spins above the stationary bedstone creating the "scissoring" or grinding action of the stones. A runner stone is generally slightly concave, while the bedstone is slightly convex. This helps to channel the ground flour to the outer edges of the stones where it can be gathered up.

The runner stone is supported by a cross-shaped metal piece (rind or rynd) fixed to a "mace head" topping the main shaft or spindle leading to the driving mechanism of the mill (wind, water (including tide) or other means).