moorstone

Etymology
From.

Noun

 * 1) A type of English granite, found mostly in Cornwall.
 * 2) * 1792,, in Danziger & Brady (eds.), Boswell: The Great Biographer (Journals 1789–1795), Yale 1989, p. 176:
 * 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.