slatestone
nounEtymology From slate + stone.
1
slate
- It [St Pinnock Viaduct] has seven piers of roughly-dressed, coursed slatestone from Westwood quarry. […] Moorswater is another masonry replacement, consisting of seven tapering piers of rock-faced slatestone with eight semi-circular arches with granite long and short voussoirs.2025 March 5, Dr Joseph Brennan, “Remembering Brunel's timber viaducts”, in RAIL, number 1030, page 58: