Cores and chopping tools are very numerous at Windmill Hill, Avebury Down, Grime's Graves, and Cissbury. They are characteristic of the industry. In the main they differ markedly from the cores of the prism industries. True prisms are rare in the one and numerous in the other; the one shows comparatively broad, the other comparatively narrow facets and flakes; the flakes of the latter being on the whole thinner and finer. It is noteworthy that when the flints of both industries have lain near the surface, those of the one in Herts., Wilts., Sussex, Norfolk, and Suffolk are almost invariably white or light blue; whilst those of the other range from light blue, through dark blue, to unchanged black or grey; with a partial exception, easy of explanation, on the coast of Cornwall.

The “lumps” may be divided into a number of species. Some were cores only, others were tools for chopping, cutting, scraping, pecking, boring, or clearing out split marrow bones; some were cores first and tools afterwards.