'Bluestone' definitions:

Definition of 'bluestone'

(from WordNet)
noun
Bluish-grey sandstone used for paving and building

Definition of 'Bluestone'

From: GCIDE
  • Bluestone \Blue"stone`\, n.
  • 1. Blue vitriol. --Dunglison. [1913 Webster]
  • 2. A grayish blue building stone, as that commonly used in the eastern United States. [1913 Webster]