There are certain areas of sandstone in the south of Scotland which are partially metamorphosed, and in these we may trace a gradual passage from highly baked felspathic sandstones with a sub-crystalline texture into a more crystalline rock which in places graduates into true granite.
"Geology"
James Geikie
The sandstones are utterly useless for road-building.
"The Future of Road-making in America"
Archer Butler Hulbert
The lowest rocks seen are at a considerable distance down the Bor-panee; they are friable sandstones that strike uniformly with the gneiss.
"Himalayan Journals V2."
J. D. Hooker