Bluish-grey sandstone used for paving and building WordNet 3.0 & Open English WordNet

Bluestone is a cultural or commercial name for a number of dimension or building stone varieties, including: basalt in Victoria, Australia, and in New Zealand dolerites in Tasmania, Australia; and in Britain feldspathic sandstone in the US and Canada limestone in the Shenandoah Valley in the US, from the Hainaut quarries in Soignies, Belgium, and from quarries in County Carlow, County Galway and County Kilkenny in Ireland slate in South Australia. Wikipedia

Petit Granit is, despite its name, a grey-bluish limestone, rather than being a true Granite. Wikipedia

A building stone of various lithologies Wikipedia Disambiguation

Blue grayish granite found in Belgium France and Deutschalnd Wikidata

Any of several bluish grey varieties of stone used for construction. Wiktionary