graystone

noun3

1. •
   A type of gray volcanic rock, typically containing feldspar and iron.
2. •
   [before a noun] Any type of gray stone, such as limestone, used in building.

   • Founded almost 50 years ago, it's an imposing graystone structure (formerly a park district office). — 2009
3. •
   A building of this kind.

   • Because graystones were more expensive to build than frame buildings and had a more substantial look and feel, they were the choice of the middle and upper classes. — 2017