Ground stone

In prehistoric Japan, ground stone tools appear during the Japanese Paleolithic, possibly predating adoption elsewhere in the Neolithic by 25,000 years.

If the stone is not tough enough to withstand hard hits and instead just flakes and cracks easily, the work done to create the tool has gone to waste.

Examples of this kind of stone include limestone, sandstone, granite, basalt, rhyolite and other igneous and cryptocrystalline rocks.

Sand would be used to help quicken the process by putting it in the partially formed hole as the sharp point was being pressed.

To put a hole all the way through a piece of stone, it would be first drilled half way in one direction and be finished on the opposite side.

Using large stones, lithic reduction would be done for long periods of time to create bowls and pots for food.

Jewelry, beads, ear spools and other decorative ground stones were a sign of high status due to the time and effort needed to make pieces of such small size and detail.

Ethnographic studies are essential to define the research question but are not enough to correctly determine the function of ground stones.

Typical methods are used to analyse them: the trace of wear and the analysis of botanical residues (starch grains and phytoliths).

This technique analyses the trace of wear left by the types of actions (pounding, grinding, cutting).

[8] Starch grains and phytoliths are botanical remains which are well preserved in archaeological context and are small enough to be trapped in the micro-crevice of a ground stone.