Bowlders of flint are broken with a sledge-hammer made of a rounded pebble of hornstone set in a twisted withe.
About ten miles north of this point, the upper calcareous, or surface rock, embraces nodules of hornstone.
The crystalline varieties, no less than the compact blue limestones, embrace numerous masses of chert or hornstone.
Among the rubbish of the diggings, fragments of hornstone occur.
hornstone is more brittle than flint and has a splintery rather than a conchoidal fracture.
The shales become dense, highly crystalline rocks of a "hornstone" type, with porphyritic developments of silicate minerals.
The occurrence of a hard variety of hornstone, which is not flint, is apparently confined to the compact, fetid variety.
Another of the dikes of the north-east of Ireland has converted a mass of red sandstone into hornstone.
It was a piece of hornstone, which I told him his tribe had probably brought here centuries before to make arrowheads of.
The sandstone has been indurated, and has assumed a texture approaching to hornstone near the junction.