Grinding Stones (磨石)

Grinding stones refer to a kind of small stone tools used to grind nuts and seeds mainly chestnut, walnut and acorn into powder in the Jomon period. Stick shaped long ones are also called grinding sticks. Pumices and ore of stones in a riverbed (base rock) assuming the spherical or disc shapes, were used unprocessed as materials, and many of these left the traces of being ground as signs of being used. Grinding stones were nearly a size larger than a fist of a grown-up man. Grinding stones were used in many cases together with stone plates, and most of them were excavated from settlements remains. Carbonized 'Jomon cookie,' the food made from nut powder, was unearthed from the Oshidashi remains of Yamagata Prefecture and the Osaki remains of Nagano Prefecture, showing that culture of powdered food became widespread in those days. Although grinding stones were excavated predominantly in the Jomon period, the appearance of them together with stone plates went back to the Paleolithic period when stone tools resembling a knife became popular.

The grinding stones (grinding sticks) found in the remains of Meso-America are especially called Mano, and they are called the same name in the remains in the North America.