File:Pestle (dorsal) (FindID 840707).jpg

English: A fine-grained hammerstone or pestle, sub-rectangular in plan and section and ovate in profile. It is slightly wider at its distal end but fits comfortably in the hand however it is held and appears to have been used to exploit several of its surfaces for different purposes. The slightly flattened ventral face is pecked and uneven, suggesting use as a hammerstone; the distal end is smooth and the right side of the implement, when viewed from the ventral face, is flat and smooth, and it is likely that both of these surfaces have been used for grinding as a pestle. At the junction between the ventral face and the right side a narrow area of the surface is roughened, suggesting that this part of the tool has been used for a more deliberate pounding or grinding process. There are several plough marks on the dorsal surface and at the proximal end. The implement is made from a local beach cobble.

Ashbee (1996) illustrates similar examples of pebbles with percussion from Halangy Down on St. Mary's, Isles of Scilly, which he suggests might have been used as pestles for food stuffs or hammers for woodworking or pulverising grit for tempering clay, on page 101, fig.48, nos.5 & 11, which were used in infill between Iron Age buildings and so must pre-date them.

Jones & Taylor (2010) illustrate a similar hammerstone and pestle on page 122, fig.60, nos.SF226 & SF230, excavated from Late Bronze Age contexts at Scarcewater, Cornwall, radio-carbon dated to c.1000- 830 BC.