US lawDistrict of ColumbiaStatutesTitle 1 — Government Organization.Chapter 1. District of Columbia Government Development.1-165.02D.C. Code § 1-165.02Potomac Bluestone.Last amended: 2015Year: 2026Length: 14 wordsOfficial source The Potomac Bluestone is hereby designated the official rock of the District of Columbia.PreviousD.C. Code § 1-165.01NextD.C. Code § 1-166.01