02. Potomac Bluestone. The Potomac Bluestone is hereby designated the official rock of the District of Columbia. (Mar. 11, 2015, D.C. Law 20-220, § 3, 62 DCR 12.)
District of Columbia Legal Code
02. Potomac Bluestone. The Potomac Bluestone is hereby designated the official rock of the District of Columbia. (Mar. 11, 2015, D.C. Law 20-220, § 3, 62 DCR 12.)