The precipice on which he stood going sheer down into the Aivron, the path along the stream left the banks some distance off, came up to where he stood, and then descended again by a deep gorge probably cut by water-power through the slaty rock.
"Prince Fortunatus"
William Black
Some varieties are slaty, and are frequently mistaken for clinkstone, which they closely resemble.
"Geology"
James Geikie
All this coast is slaty shale; there is a miniature quarry just away to the west round the next headland, and the materials lying to hand were not likely to be neglected in days when transport was more of a consideration than now.
"Cornwall"
G. E. Mitton