moorstone
nounEtymology From moor + stone.
1
A type of English granite, found mostly in Cornwall.
- Most of them are what is called moorstone, a kind of granite, but which is so damp that it must, when built in the wall of a house, be lined with brick or other stone.1792, James Boswell, in Danziger & Brady (eds.), Boswell: The Great Biographer (Journals 1789–1795), Yale 1989, p. 176