WEST CONSHOHOCKEN, Pa. – Petrography – the detailed description of rock – now has a new standard for dimensional stone.

ASTM International announced the release late last year of ASTM C1721 – the Guide for Petrographic Examination of Dimension Stone. The new standard, developed by the group’s Committee C18 on Dimension Stone, is under the jurisdiction of Subcommittee C18.01 on Test Methods.

C1721 will serve as a standard to guide petrographers who analyze dimension stone in describing, analyzing and reporting the characteristics important to architects and engineers in determining how a stone will behave or has behaved in service, said Laura Powers, a petrographer with Wiss, Janney, Elstner Associates Inc. of Northbrook, Ill., and an ASTM member.

“In this standard, the petrographer who examines stone is directed to determine the proper scientific classification and to investigate characteristics important to the performance of the stone,” said Powers, who notes that there are certain performance expectations for any type of stone.

“When purchasing dimension stone, the purchaser, often through an architect, can reference ASTM C1721 and be confident that characteristics of the stone relating to its future performance are identified and reported using standardized evaluation techniques,” says Michael Scheffler, also of Wiss, Janney and a C18 member.

Scheffler says all interested parties are welcome to join C18.01 in working on future revisions to ASTM C1721, particularly in expanding the description of more-advanced evaluation techniques now just briefly described in the standard.

The next meeting of ASTM Committee C18 will be April 21-22 in St. Louis.