Lithic comparison has been difficult but not impossible,

as much of the modification marks have softened and the more regular finds as axe and arrowhead are few and not as straight forward as one would expect.

Another difficulty arises as this area has been fed by the edge of the last Ice-age from the North and the rivers from the South and East.

The lithics, pebbles, and small stones show sorting and clustering.

The chert is very varied with some selective pieces from quarries/mines near Maastricht, to red flint from high up in the North. Or Lava stone from the south.

Also there is a large amount of selected stones for their appearance or usability  This can be delicate, attractive, associative or useful.

Many stones are halved in a logic way to mankind, but illogic to natural.