Wiktionary
roadstone
n. Any type of stone or stone product, such as shingle, flints, crushed stone, etc used as a construction material for building roads.
Usage examples of "roadstone".
They were covered in blood and more was dripping constantly, some splattering on to soiled boots, some on to the sun-dried roadstones, cutting new rectangular valleys along the ancient weathered joints.
And he didn't want to condemn himself to fifty years of heavy sponges, chewy pastry and rock cakes that seemed to have come straight from the local roadstone quarries.