This stone piece is known as the "Raha" (or grinder), an ancient traditional grinding machine that was used to grind and crush various types of grains. Wikipedia Wikipedia +1 Features and Design of the Raha: Components: It usually consists of two heavy, circular, rough stones placed one above the other. Middle Hole: There is a hole in the center of the upper stone through which the grains to be ground are introduced. Side Hole: Your picture shows a small hole on the edge of the stone, which is for inserting the wooden handle used to manually rotate the upper stone. Working Mechanism: The upper stone rotates around a fixed axis (called the Raha's pole) fixed in the lower stone. Saudipedia Saudipedia +2