Roughly two-thirds of an assemblage of 156 whetstones from three collections representing two late Roman sites at Silchester can be assigned geologically to the Brownstones (Devonian), Pennant sandstone (Carboniferous) or Stonesfield Slate (Jurassic), imported from the west and north into the town as roof-tiles. The latter were put to further, secondary use as whetstones, some small and portable but others large and laid flat and kept stationary. The whetstones are polished through use, typically on both faces, and a high proportion carry grooves. On some the grooves are short and fine and could represent the sharpening of such items as pins, needles, meat skewers, styli and engraving tools. These grooves are typically found on whetstones from Insula IX, where artisanal and, at best, ‘light-industrial’ activities are recorded. At the forum-basilica, by contrast, the whetstones are more substantial and typically show large grooves of two kinds that point to the shaping and finishing in considerable numbers of iron objects such as knives, cleavers, swords and even possibly ladles. The industrial activity at this site had a distinctly ‘heavier’ quality. The biography of these whetstones — objects seemingly simple and unpretentious — was complex, wherever they were found.

Excavated in 1992–4, the villa yielded a portion of a whetstone which, on the basis of general shape, the presence of rebated long edges and microscopic petrography in thin-section, was with little doubt made from a sandstone in the Weald Clay Formation (Lower Cretaceous) of the north-west Weald. It is representative of a widely recorded, major stone-based industry in Roman Britain, with finds known to range from the Channel coast to the northern frontier zone.