Quartz—a mineral composed of silicon dioxide, or silica: SiO₂
Sandstone—a sedimentary rock composed chiefly of quartz grains
Sedimentary—formed from particles that were transported by water or wind and deposited in layers
Volute—a scroll-like ornament on an Ionic column capital
Further Reading
Acid rain: The facts, 1988: available from Inquiry Centre, Environment Canada, Ottawa, Ontario, Canada K1A 0H3.
Amoroso, G.G., and Fassina, V., 1983, Stone decay and conservation: New York, Elsevier, 453 p.
Hannibal, J.T., and Park, L.E., 1992, A guide to selected sources of information on stone used for buildings, monuments, and works of art: Journal of Geological Education, v. 40, p. 12-24.
Pickering, R.J., 1987, Acid rain: U.S. Geological Survey Open-File Report 87-399.
U.S. Geological Survey, Building stones of our Nation’s Capital: Reston, Va., U.S. Geological Survey general-interest publication.