About Austin Stone and Architectural Limestone

Austin Stone is a type of masonry material named after the limestone rock quarries in Austin, Texas. On older homes, natural Austin stone is set in orderly rows or irregular patterns. On newer buildings, the "neo-Austin Stone" is often a man-made material manufactured from Portland cement, lightweight natural aggregates, and iron oxide pigments. This imitation stone is frequently applied as a veneer.

Today the name implies a uniformly white-colored stone or stone-like material — a generic term for the pure white limestone once associated with this Texas town in the 19th century. The Comal County Courthouse in New Braunfels, Texas between Austin and San Antonio is a good example of a public building made of native limestone. The pitch-faced, rusticated texture was common to the Romanesque Revival style of the 1898 period. The construction material provides a clean, sanitary look for both interiors and exteriors. Often, residential exteriors combine areas of stone with areas of wood siding.

Texas Limestone

Austin stone is a kind of "look" by manufacturers of synthetic stone, produced to appear as if it is real stone cut from the pure white limestone quarries of Texas.

"Lime was big business in Central Texas," writes Austin columnist Michael Barnes. Limestone quarries supplied construction materials for a growing nation's buildings from the mid-1800s until well into the 20th century. Quarries can cut stone to most any size, blocks or thin. "Austin white limestone — along with other color variations — can be finished rough, called 'rusticated,' or sawed, or smooth and finely dressed, dubbed 'ashlar.'"

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Where Things Come From: Rock Materials

By Andrew Alden

Cast stone as opposed to cut stone is the more popular choice at home improvement stores like The Home Depot. Veneerstone supplies a variety of colors of Austin stone composites. To "cast" means that the cement mixture is put into a mold that is created from actual cut stones. The resulting material is only about 1.5 inches thick — to be used decoratively, but not structurally. This construction material has been around long enough that Historic Preservation Brief 42 is dedicated to help us understand how to preserve it. "While the term 'artificial stone' was commonly used in the 19th century," preservationist Richard Pieper writes, "'concrete stone,' 'cast stone,' and 'cut cast stone' replaced it in the early 20th century. In addition, Coignet Stone, Frear Stone, and Ransome Stone were all names of proprietary systems for pre-cast concrete building units...."

The Australian building supply company Boral Limited has a trademark on the name Cultured Stone for their Austin stone products.

Although Austin Stone may never have been a limestone color, the name has become descriptive of a white, pure limestone. Like paint colors, stone fabricators like to introduce new hues to their products — or at least new names. What may have been "Austin Stone" one year might be "Texas Cream" the next. Other names include "creamy limestone" and "Chardonnay." Austin stone is often in the white/yellow category compared with white/grey hues sometimes called "glacier." Other color names may include Rattlesnake, Texas Mix, Nicotine, Tumbleweed, and Sunflower. One can use imagination to give a descriptive stone palette name to a yellow tint.

Texas quarries still do the business of cutting stone. Since 1888, Austin White Lime Company has been a supplier of quicklime plaster, a calcium oxide substance that results from heating high quality, pure limestone. Since 1929, Texas Quarries has been quarrying and fabricating (e.g., sawing large blocks to various sizes) Texas limestone. "We quarry and fabricate limestone indigenous to Texas," the company proudly claims: "Cordova Cream and Cordova Shell from the Hill Country; Lueders Buff, Gray, and Roughback from the Abilene area." Cordova and Lueders are more general place names, like Austin. The family-owned Texas Stone Quarries includes Cedar Hill Cream limestone and Hadrian limestone. Limestone containing the shells of sea creatures (sometimes called shellstone or shell limestone) is popular for upscale coastal communities, such as some of the Florida home designs by Taylor and Taylor.

Limestone Quarries Beyond Texas

Most of the limestone used in America does not come from Texas, however. Engineering expert Harald Greve tells us that almost "80% of the dimension limestone used in the United States is quarried in the state of Indiana." The colors of Indiana limestone, however, are generally off-white gray and buff. Limestone of different shades is found around the U.S. and throughout the world. Some architects have long favored designing with Travertine, a colorful form of limestone; and the popular Jura Stone, a limestone found in Germany, is so rich looking that it's often called marble.

Perhaps the greatest structures built with limestone blocks are not in the Western world at all — the Great Pyramids of Egypt.

SUMMARY: Questions to Ask Before You Begin With Stone

Achieving a "look" with stone involves answering many questions about color, finish, shape, and application.

• For exterior or interior use?
• For cladding, veneer, or structural use?
• Real (natural) stone or fake (i.e. faux) polyurethane-based foam panels?
• Thin stone veneer, cultured stone, or cast stone?
• How will the stone be applied? (dry stack or grout / mortar?)
• What finish type? (e.g., polished or rusticated?)
• What pattern type will the stones be laid on the wall?
• Where is the color in real natural stone and manufactured stone? Is the color only in the top layer?
• Do I need a mason or can I do it myself?

Sources

• Barnes, Michael. "We Built This City: Historical Austin Materials," May 16, 2013 at https://www.austin360.com/entertainment/built-this-city-historical-austin-materials/69u97kltXAmj36sOiCsIvN/ [accessed July 8, 2018]
• History, Austin White Lime Company at www.austinwhitelime.com/
• History of Cast Stone, Cast Stone Institute, http://www.caststone.org/history.htm [accessed July 7, 2018]
• Pieper, Richard. Preservation Brief 42, The Maintenance, Repair and Replacement of Historic Cast Stone, National Park Service, https://www.nps.gov/tps/how-to-preserve/briefs/42-cast-stone.htm
• Greve, Harald. "Quarrying and fabricating Limestone," Masonry Construction, Publication #M99I017, September 1999, http://www.masonryconstruction.com/products/materials/quarrying-and-fabricating-limestone_o [PDF at www.masonryconstruction.com/Images/Quarrying%20and%20Fabricating%20Limestone_tcm68-1375976.pdf]
• All About Jura Limestone / Marble, Globalstoneportal, http://www.globalstoneportal.com/blog/analysis/all-about-jura-limestone-marble [accessed June 5, 2016]