Brownstone is a brown Triassic–Jurassic[1][2]sandstone that was historically a popular building material. The term is also used in the United States and Canada to refer to a townhouse clad in this or any other aesthetically similar material.
^Muessig, Karl W. (2007). "Unearthing New Jersey"(PDF). New Jersey Geological Survey Newsletter. 3 (1): 1. Archived from the original(PDF) on 13 December 2014. Retrieved 12 December 2014.