District of Columbia Code Division I. Government of District. § 1-165.01. Legislative findings.

(a) Potomac Bluestone is a metamorphic rock that has a long and distinguished history in the District of Columbia.

(b) Before the founding of our nation, Potomac Bluestone was quarried by Native Americans and used by early colonists. Later, District residents, including Italian immigrants and African Americans, followed in the footsteps of the first Americans and also quarried this ancient and important rock.

(c) Potomac Bluestone has been used extensively in construction in the District of Columbia.

(d) Potomac Bluestone was used as the foundation for the White House, the Capitol, and the Washington Monument.

(e) Many houses in the northwest section of the District are also made of Potomac Bluestone, including the Old Stone House in Georgetown, which was built in 1765.

(f) Other notable area structures with Potomac Bluestone are Georgetown's Healey Building, St. Elizabeths Hospital, the Chain Bridge abutments, and the sea wall at Hains Point. The rock is also at the National Zoo, in the Panda House, the Elephant House, and the Mane Restaurant.