Ohio State Stone
Sandstone is one of the clastic sedimentary rocks, formed from the eroded remnants of older rocks. As the name suggests, it is made up of sand, so it falls between siltstone and conglomerates in grain size. The name may suggest a crumbly or impermanent stone, but the best sandstone compares well with granite for hardness and density.
Color ranges from white to buff and yellow to red and brown. Berea sandstone, named for the town where it was quarried, is high in silica, giving it excellent bearing strength as a building stone. Another feature of the stone is the angularity of its grains, which makes it useful for abrasion and is the reason grindstones made from sandstone were in demand for a century.
A STATE SYMBOL
While Ohio has not designated an official state stone, the selection of the Berea sandstone seems obvious. This high-quality stone is one of several varieties of sandstone that are abundant in the state and were used for building before Europeans ever arrived—a Native American fortification built from Berea sandstone has been dated at over 600 years old. Berea sandstone has been quarried in great quantity in Ohio since the 1840s and has contributed significantly to the state’s architecture and economy. The Berea grindstone works were a major industry, using a lathe invented by John Baldwin, one of the founders of both the town of Berea and the Baldwin Institute, now Baldwin-Wallace College.
Quarries in the northern part of Ohio were producing a million tons of sandstone a year as early as the turn of the 19th century, and production doubled by the 1950s. Berea sandstone was shipped across the U.S. and Canada for use in building construction. The Buckeye Quarry in Amherst produced stone for over a century and was believed to be the largest sandstone quarry in the world; the Amherst area was known as "the Sandstone Center of the World," and quarries there still produce Berea sandstone.
Sandstone is a sedimentary rock that forms by accretion (accumulation) of grains of sand. The grains, themselves remnants of much older rocks, typically accrete in layers underwater or in deserts, as well as in glacial outwash. As layers are buried under layers, pressure accumulates, compacting the grains of sand closely. However, the temperatures and pressures to which sandstone is subjected are much lower than those for igneous and metamorphic rocks; the grains of sand do not melt or deform. When dissolved silica or calcium carbonate fills the spaces between the grains, it cements them together, forming the stone.
Sedimentary rocks cover about 80 percent of the earth’s land and most of the ocean floor, yet they form a thin skin, accounting for only eight percent of the volume of the earth’s crust. Sandstone specifically makes up about a quarter of this material. Because it lies at the surface, it is readily available all over the world. In 2005, U.S. quarries sold 192,000 metric tons of dimension (cut in shapes) sandstone in the domestic market, of which roughly one-fourth was rough stone and the rest was dressed stone. Ten tons of U.S. dimension sandstone were sold in Canada.
Sandstone is used in architecture because of its beauty, strength, and versatility. Its resistance to erosion and weathering makes it popular for outdoor applications, including foundations, walls, and paving stones. Its heat resistance makes it an excellent choice for fireplaces, and its resistance to salt air makes it useful for buildings near the sea. The variety of colors, and the interesting striations that occur in some sandstones, give the material great appeal both for structural applications and for carved decorations. In addition, crushed sandstone is a source of silica for the manufacture of glass. Poorer quality stone may be crushed to make a component of concrete.
In Ohio, the high-silica Berea sandstone lends itself to a wide variety of applications. Over the past two centuries, it has been used for construction of buildings, dams, and canal locks; for furnaces to smelt iron; for grindstones; for glassmaking; and as aggregate (crushed stone) for concrete and other industrial applications.
Stonehenge, the Neolithic astronomical monument in the United Kingdom, is built of massive sandstone pillars. The Great Sphinx is among Egypt’s ancient monuments made of sandstone. In China, the Great Buddha at Leshan is carved out of a red sandstone rock face. The famous brownstone rowhouses of East Coast cities are made of brown sandstone quarried in Pennsylvania and Connecticut. Natural monuments are also made of sandstone; the most famous example may be the eroded mesas of Monument Valley in Utah and Arizona.
A handsome example of Berea sandstone is the Auglaize County courthouse in Wapakoneta, Ohio.
Chemical Formula: SiO2
Color: Varying shades of reddish-brown
|Author: World Trade Press|