Frequented by more deer than people, the NIST stone test wall lives a fairly isolated existence. Out among the trees and the grass on the south end of the Gaithersburg, Maryland, campus, it cuts an imposing and visually bizarre figure. Set in the mortar of its technicolor face are more than 2,000 square and rectangular stone samples showing off practically every naturally occurring type and color of stone. Nearly 70 years old, it is the world’s longest-running weathering experiment for stone samples, as well as a reminder of the symbiotic relationship between science and industry.

 …