New Jersey State Stone
Stockton sandstone is a fine-textured arkosic sandstone (sandstone containing feldspar), sometimes with traces of mica. Its color is pinkish brown. In popular terms, it is a brownstone, a material much in vogue in the 19th century for the exteriors of better houses and public edifices.
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. Sandstone’s color ranges from white through buff and yellow to red and brown. The color of Stockton sandstone comes from hematite (iron oxide).
A STATE SYMBOL
While New Jersey has not designated an official state stone, Stockton sandstone has great historic, economic, and cultural significance for the state. New Jersey’s several brownstone quarries produced thousands of tons annually of the handsome Stockton sandstone, in addition to allied varieties such as Belleville and Passaic.
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 (building) 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. The resistance of the best types to erosion and weathering makes sandstone 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.
Stonehenge, the Neolithic astronomical monument, 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 entire village of Collonges-la-Rouge, in Limousin, France, is built of red sandstone; a popular tourist attraction, the picturesque village was designated a historical monument in 1942. Natural monuments are also made of sandstone; the most famous may be the eroded mesas of Monument Valley in Utah and Arizona.
The oldest and most famous building on the Princeton University campus, Nassau Hall (built in 1756), is made of Stockton sandstone. The structure has suffered from the Stockton sandstone’s susceptibility to degradation in the damp and at times acidic air of New Jersey.
Chemical Formula: SiO2
Color: Varying shades of reddish-brown
|Author: World Trade Press|