Grinding Stones

1 grinding stone
and 2 top stones
- Narrandera, NSW

The grinding stone is the largest stone implement in the Aboriginal stone tool kit. The grinding stone above is at least 60cm by 30cm, and the top stones are approximately 10-15cms in diameter. It is made from a quarried slab of sandstone, but they can also be made from largish flat pebbles. The two top stones are also made from a particular type of sandstone. Often grinding stones are oval in shape, however this can vary as the stones are trimmed into the shape wanted by its owner. The grinding stone in the collection is oval-like but also resembles a pear shape.

The top stones (also known as upper stones) have a flat surface as it has been worn flat and smooth on its underside. While the grinding stone (also known as lower stone) has a deep groove or hollow, worn into the stone. These use-wear patterns occur over time from grinding different materials.

Grinding stones were used for a variety of different purposes. However, I have classed it in the Food Preparation function group, but this does not restrict its usage to food alone.

Girls preparing seeds at Yirrkalla, Arnhem Land
(McCarthy, 1976: 75)

The two girls in the above photograph are pounding and grinding the seeds with their top stone, which appears to be a river pebble of some sort. Therefore, the one implement can be used in a variety of different techniques to achieve different degrees of texture, that is really coarse or really fine.
Being able to control this degree of texture, allows different types of grains, seeds, ochres and other materials to be ground for either food preparation or ceremonial purposes such as ochre body painting or rock art. (Click here to see some Paleolithic cave paintings in France, using charcoal and different types of ochre like substances)

Grinding Stones were not carried around with the Aboriginal tribes (who moved from site to site depending on the season and food sources available), but they were placed upside down - to stop erosion from rain and wind, and left in a memorable spot to be used again upon the owners return. This was extremely sensible as the grinding stones are very heavy and can way upto 14 Kilograms in weight (even more if a really large implement).