Dimension stone

Where Found

Dimension stone, or natural stone, is mined in quarries around the world. The largest concentrations are found in China, India, Italy, Canada, and Spain. In the United States, a country that produces less than 15 percent of the worldwide supply (although it is the dominant market for the stone), quarries are found in thirty-five states, principally (in order of percentage) Indiana, Vermont, Georgia, Wisconsin, and Massachusetts.

Primary Uses

Dimension stone is used primarily for domestic decorating and home improvements in upscale housing. It also provides massive block foundation support for large-scale engineering projects, as well as material for monuments, memorial stones, and walkways.

Technical Definition

Dimension stone is any natural rock—igneous, metamorphic, or sedimentary—precisely cut from a quarry to a specific size (in blocks or slabs) for a specific function (as opposed to crushed stone, which is fractured rubble blasted from quarries to facilitate its removal). Commercially, granite is the most widely used (about one-third of the dimension stone quarried), followed by limestone, marble, sandstone, and, to a much lesser extent, slate and travertine. The decision about which class of dimension stone is to be used is based on color and texture as well as appearance and durability.

Description, Distribution, and Forms

Because dimension stone requires precise mining, must maintain a usable appearance throughout the excavation process, and has a comparatively high expense in transportation, it accounts for roughly only 2 percent of the total rock mined annually. In the United States, for instance, approximately 1.4 million metric tons of dimension stone are mined annually. Dimension stone can be either rough block (for heavy construction and residential foundations) or dressed block (for statuary, paving stones, and domestic decoration), with its distinctive luster. In fact, finish also is used to classify types of dimension stone. In addition to being reflective, surfaces can be pitted, nonreflective (both smooth and rough), and patterned (often produced by hand).

The four principal types of dimension stone—granite, limestone, marble, and sandstone—are graded by color, grain, texture, mineral patterns and swirls, natural surface finish, durability, strength, and mineral makeup. For instance, dimension granite, an igneous rock, is valued for its relative availability; its durability in the face of weathering and environmental pollution, specifically acid rain, because it is most often used for exterior construction projects; its uniform texture; its hardness; and its variety of colors. Dimension limestone, a sedimentary rock composed largely of calcite, is easy to cut into massive blocks and, although not impervious to acid rain, is remarkably durable (the Pyramids at Giza are made of dimension limestone). However, because of dimension limestone’s enormous weight, it is used primarily for foundations and smaller buildings. Dimension marble is a metamorphic rock that is both durable and strong. With its exquisitely smooth, polished surface, marble can be cut into large blocks (up to 63 metric tons) and used to create spectacular public buildings (for instance, the Taj Mahal and the Lincoln Memorial). Dimension sandstone, a sedimentary rock, is most often light gray or yellowish-brown; however, its tendency to streak because of weathering creates striking, aesthetically appealing striation effects. Its surface is coarse and finely grained. It is particularly fragile, susceptible to weathering, and has to be replaced; thus it is limited in its uses.

History

Using carefully cut, ponderous blocks of durable rock for major engineering undertakings dates to antiquity in both the Far East, predominantly China, and the Mediterranean basin, most notably the stunning pyramid constructions in Egypt, the marble temples around Athens, and the mosques of Turkey. By the Renaissance, rich mineral deposits of marble and granite in Italy and Spain were being utilized to construct great cathedrals and a wide variety of public buildings, courthouses, and palaces. Because of the precise method for cutting the stone, as well as the often extraordinary cost of transporting a massive amount of chiseled rock without damaging its integrity, dimension stone was used almost exclusively for public projects financed by monarchies, the Catholic Church, or wealthy aristocrats.

Large deposits of granite, limestone, and marble found in New England and in the Middle Atlantic states, most notably Tennessee and Indiana, made dimension stone affordable in the New World. Dimension stone played an enormous role in shaping the look of (and providing the architectural support for) many public edifices and private residences across the United States. By the mid-twentieth century, however, newer building materials—reinforced concrete, aluminum, and steel—eclipsed dimension stone. That changed dramatically when environmental concerns about the pollution created by the production of those construction materials returned attention to all-natural dimension stone. In addition, the home building boom in the United States during the 1990’s created a market of upscale consumers interested in using natural stone to decorate their custom-built homes. In the same decade, interest in dimension stone was bolstered by large-scale public construction projects, most notably the Denver International Airport, the Korean War Veterans Memorial, the National World War II Memorial, and the Franklin Delano Roosevelt Memorial (the latter three are located in Washington, D.C.).

Obtaining Dimension Stone

The process of obtaining dimension stone—drilling, extracting, cutting, shaping, and polishing—is usually tailored to follow a specific mining order; dimension stone is seldom mined without a contract for a particular project. Since the 1960’s, extracting dimension stone has been enhanced, and made comparatively easy, by significant developments in engineering tools. Unlike the excavation of crushed stone, which relies on indiscriminate detonations and heavy machinery, the recovery of usable dimension stone requires care. Each type of dimension stone requires its own methodology depending on the needs of the construction project, the depth of the mineral deposit, and the mining operation’s financial resources. The methodology is further impacted by the location of the vein—whether cutting into a hill (called a bench quarry) or digging into the flat ground, operations that can go to 90 meters.

Obtaining dimension stone begins with limited blasting. Then jet piercers, which use a high-velocity jet flame—a concentrated, highly combustible blast of oxygen and fuel oil shot through a nozzle under enormous pressure—channel into the quarry face. In the case of marble, limestone, and sandstone, safer electrical drilling machines with steel chisels that chop channels into the walls and cut away the desired blocks are frequently used; this method is more time-consuming. In the case of granite and marble, once channels are created, large blocks are pried from the quarry face or extracted from the quarry mine and cut on site into usable shapes (ranging from 0.3 to 18 meters long and 4 meters thick), called mill blocks. Each block is then removed from the quarry area with derricks. In turn, these blocks are processed for their specific project, that is, given the appropriate shape, size, dimension, and finish by certified masons who use a variety of precision saws. Diamond saws are used most often because of their hardness and their ability to cut intricately and carefully.

Uses of Dimension Stone

Despite the availability of less expensive substitute building materials, the extraordinary expense of such precisely cut stone, and the care needed during its transportation, dimension stone has maintained its position within the engineering and architectural fields for close to three millennia. Slabs of cut stone, most often granite or sandstone, provide a reliable, durable, and attractive foundation for both buildings and residences. However, the use of the stone for spectacular building projects is the use most often recognized by people. Dimension stone such as granite and marble is most associated with grand public spaces and with important monuments dedicated to historically significant people and events, public buildings (like banks and government facilities), cathedrals, grand private homes, upscale hotels, cemetery headstone markers, and elegant mausoleums. In addition, thinner cuts of dimension marble are used for cladding, the outer skin of stone applied to buildings to protect the foundation stone and to give the building an aesthetic quality.

Dimension stone creates an elegant, tasteful, and earthy feel to home interiors. It provides tops for kitchen counters and bathroom vanities as well as material used for staircases and ornamental arches in homes where owners are interested in creating distinctive—and expensive—custom-designed interior effects. Because no two slabs of dimension stone are exactly alike, interior effects can be both striking and individual. Because of the wide variety of textures and colors in natural stone, homeowners can complete virtually whatever decorating motif they conceive by using cut stones for floor tiles, walkways, flagstones, ornamental statuary, and roofing shingles.

Bibliography

Adams, Heather, and Earl G. Adams. Stone: Designing Kitchens, Baths, and Interiors with Natural Stone. New York: Stewart, Tabori & Chang, 2003.

Bell, Ron. Early History of Indiana Limestone. Bloomington, Ind.: AuthorHouse, 2008.

Dupré, Judith. Monuments: America’s History in Art and Memory. New York: Random House, 2007.

Greenhalgh, Michael. Marble Past, Monumental Present: Building with Antiquities in the Mediaeval Mediterranean. Boston: Brill, 2008.

Isler, Martin. Sticks, Stones, and Shadows: Building the Pyramids. Norman: University of Oklahoma, 2001.

U.S. Geological Survey. Minerals Information: Dimension Stone Statistics and Information. http://minerals.usgs.gov/minerals/pubs/commodity/stone‗dimension/