Definition of "greystone"

21 SATURDAY Thirty-nine years ago, Margaret Burroughs founded the DuSable Museum of History and Art on the first floor of her South Michigan Avenue greystone, with the pantry serving as its library.

2000 October 20, Cara Jepsen, “Datebook”, in Chicago Reader‎

Here and there the bogland showed a darker tint, and at his feet, cupped out in the smooth greystone, lay a sheet of water.

1919, H. C. (Herman Cyril) McNeile, Mufti‎

The walls were of native greystone in its natural roughness; all over the front and one angle the American ivy climbed and waved, mounting to the tower; while at the back, the closer clinging Irish ivy covered the little "apse," and creeping round the corner, was advancing to the windows, and promising to case the first one in a loving frame of its own.

1865, Susan Warner, Melbourne House, Volume 1‎