Seneca Sandstone

Seneca Sandstone

A siltstone (sedimentary rock) of the late Triassic Period

“It’s about the prettiest stone there is,” in the words of one native and lifelong resident of Montgomery County, Maryland whose home overlooks the Potomac River near where Seneca Sandstone was once quarried. Seneca Sandstone, favored for its strength, durability, and dignified appearance, was used to build the Smithsonian Castle in Washington, D.C., and many other pre bellum structures in the nation’s capital, including many rowhouses. The stone was also used for heavy load-bearing structures like railroad trestles, as well as the locks along the C&O Canal, which runs 184 miles up the Potomac from Washington, D.C. After the Civil War, tastes changed, and the handsome redstone from the Potomac fell out of favor, giving way to lighter colored stones like the granite from Deer Isle, Maine, a specimen of which is also among the Museum's holdings.