Grindstones can be used for grinding seed into flour for bread making, cracking of animal bone for the extraction of marrow, for pulverising cartilage and small animals such as lizards. They were also used for grinding up pigments such as ochres, to prepare resin and bush tobacco, and to sharpen and smooth wooden and stone tools.
The larger stones which form the lower platform are called Millstones. With deep indentations, they hold material to be ground up by the smaller stones, otherwise known as Mullers.
The grinding stone and top stone shown here were used by Indigenous women in the semi-arid region of New South Wales to grind seeds from grasses, trees, shrubs, succulents and ferns to release the starch for cooking purposes. The flour produced was mixed with water and eaten as a paste, or cooked in the coals of a camp fire and eaten as cakes or loaves.
The stone is indicative of grinding stones used in the region for thousands of years. Fragments of grinding stones dating back 30,000 years to late in the Pleistocene Epoch have been found at the archaeological site at Cuddie Springs in western NSW.
Large grinding stones such as this one were designed to be left at a camp site for use the next time the group moved there. Smaller grinding stones were carried between sites. Grinding stones were not abandoned when they became worn and smooth through use. The stone would simply be roughened again so it was once again suitable for its function.
Grinding stones used to grind seeds and nuts have been found throughout Australia, particularly in arid and semi-arid areas where Indigenous people were reliant on grass seed for starch as their staple food. In some areas of Australia grinding utensils were made from heavy hardwoods.
Grinding and top stones such as these are similar to the pestle and mortar still used today for grinding herbs and spices. They thus represent a food preparation utensil used throughout the world and still in use in most societies.