ASTM Committee C18 on Dimension Stone was formed in 1926. C18 meets twice a year, usually in April and October, with about 20 members attending over two days of technical meetings capped by a tour of a quarry and stone fabrication mill. The Committee, with a current membership of approximately 100, has jurisdiction of over 25 standards, published in the Annual Book of ASTM Standards, Volume 4.07. Committee C18 has 5 technical subcommittees that maintain jurisdiction over these standards. Information on this subcommittee structure and C18's portfolio of approved standards and work items under construction are available from the List of Subcommittees, Standards and Work Items below. These standards have and continue to play a preeminent role in all aspects important to the effective standardization of dimension stone, including, testing, specifications and construction practices.