silex

The knives of silex, which I found last year in such great quantities, are as yet but rarely met with in this excavation.

The combination of silex or alumina and an alkali in proper portions always yields a fusible, easy-running compound.

The bed of the road was first properly prepared, and then it was paved with polygonal blocks of blue basalt called silex.

Silex is another volcanic stone very little used for building, but entirely for paving the roads both ancient and modern.

Then, on the terrace above, there is an arcade paved with blocks of silex, and on one side shops.