Origin of hornstone
Examples from the Web for hornstone
About ten miles north of this point, the upper calcareous, or surface rock, embraces nodules of hornstone.
It was a piece of hornstone, which I told him his tribe had probably brought here centuries before to make arrowheads of.The Maine Woods|Henry David Thoreau
The geological locality of hornstone is remarkable; for it occurs in both ancient and recent formations.
The hornstone which occurs in secondary limestone is called chert by the English miners.
Another of the dikes of the north-east of Ireland has converted a mass of red sandstone into hornstone.A Manual of Elementary Geology|Charles Lyell.