File:Incised slate (lozenge) (FindID 971656-1074534).jpg

English: Incised slate disc made from a piece of micaceous silty slate, possibly with volcanic ash content, from the Gramscatho formation, and the brown staining is the result of a ferruginous deposit penetrating along the cleavage of the rock (Roger Taylor in S.Taylor (ed.) Down the Bright Stream: the Prehistory of Woodcock Corner and the Tregurra Valley, forthcoming).

The upper face is decorated with incised lines to produce a chequerboard pattern in which alternate squares have been either left blank or filled with a cross-hatched grid of varying number of smaller squares. Several flint tools were found in association with the disc and it is possible that some of these were used to incise the lines. The design appears to have been initially 'sketched out' with fine lines, which are still visible on several places, and then finished by repeated incision to create the more deeply carved lines. The surface of the stone appears to have become delaminated in one square in the top right-hand quadrant; there is evidence to suggest that that was done deliberately in an attempt to erase a square that had been incorrectly cross-hatched. In some places the design appears to be 'unfinished', such as the bottom left-hand corner where a square has been left unfilled. The design appears to be truncated at three of the four corners, either by the application of partial squares or by deliberate trimming after the decoration was complete. Several areas of the surface have been abraded and there are some fine scratches visible on the surface together with a deeper, diagonal scar which appears to predate the carved decoration.

The lower face does not display the same evidence of initial 'sketching out' or repeated incision and is consequently less deeply worked and relatively faint. The more fluid, freehand decoration is of a pattern of irregular conjoined lozenges with triangles at the upper and lower sides where the design meets the bounding lines. These have been infilled with a range different patterns including parallel chevrons, herringbone motifs, parallel lines, cross-hatching, concentric triangles and lozenges. Several areas, such as the top left, show signs of 'mistakes' where the flint engraving tool has slipped. Some areas, such as the triangles on the right-hand edge, appear to have been left unfinished. These is less abrasion than on the upper side.

The differences in style and execution between the two sides may suggest that they were decorated at different times or by a different hand (Antonia Thomas, Mobiliary Art in S.Taylor (ed.) Down the Bright Stream: the Prehistory of Woodcock Corner and the Tregurra Valley, forthcoming).

The disc measures 192.5 mm long x 173.5 mm wide x 12 mm thick and weighs 724 g.

Flaked stone discs are commonly described as 'pot lids' in archaeological reports as they have often been found associated with ceramic vessels, and this uniquely decorated disc was recovered from a pit which also contained sherds of Grooved ware pottery with chevron incised decoration and vertical bands of raised impressions which has been radiocarbon-dated to the Later Neolithic, between 2800-2600 cal BC.

Published in Andrew Meirion Jones and Marta Diaz-Guardamino (2019) Making a Mark on pages 60-1, 188 & 200.