Due to its strength and durability, stone has been a key element in all types of buildings and structures since the beginning of architecture and construction. Not only is it a particularly useful element, but the wide variety of colors and textures of stonework found all over the world gives rise to an extensive list of various aesthetics. Many common characteristics of historic stone fall from this commonality of strength and beauty among different types of stone.
Since stone is difficult to transport due to size and weight, stones will often be sourced relatively close to the area in which the building is to be constructed. Consequently, specific characteristics of stone will vary depending upon the region in which the stone is found. For example, igneous rock is found near volcanic activity and differs from sedimentary rock which is found near water sources. Accordingly, the different types of stone which come from igneous rock will have different specific characteristics than the stones which are by nature sedimentary.
However, there are general qualities which are characteristic of all stones used in buildings. Some common characteristics include appearance, weight, durability, strength, hardness, porosity, and resistance to fire and electricity. It is important to take these and other characteristics into account when constructing or restoring a historic building. Misunderstanding stonework can result in more harm than good when it comes to restoration or new design.
Union Station in Washington D.C. was built using White Granite from Bethel, Vermont.
Common Characteristics
Appearance
When it comes to historic buildings, beauty is just as important as strength. The visual appeal of stone contributes significantly to a structure’s overall aesthetic and its ability to evoke historical authenticity. For this reason, it is vitally important to choose a stone that will fit with the building’s overall appearance. Color, warm or cool tones, texture, and pattern are all important factors that play a part in choosing the right stone.
Natural stone also offers a variety of finishes, from the smooth polish of marble to the rough, weathered surface of sandstone. Over time, some stones develop a patina, adding depth and historical character. A well-chosen stone ensures the building remains visually compelling while preserving its architectural authenticity.
Weight
A stone’s weight directly affects its structural strength and durability. Although heaviness makes transportation difficult, it is a distinguishing factor of stone which cannot be found in other architectural elements. It can withstand immense weathering and wear in a way that wood or other architectural elements cannot. Granite is among the heaviest stones which has been used throughout the centuries, and its weight also contributes to the stability of structures, making stone ideal for load-bearing walls, columns, and foundations. Despite the challenges associated with transportation and installation, the enduring strength of stone justifies its use in historic and monumental architecture.
Durability
The durability of stone is primarily due to its compactness and homogeneity, setting it apart from other building materials. This means that the minuscule particles of the stone are very close together and generally all the particles are of the same material. The compactness of the stone results in little room for absorbing liquids which is ideal since absorption will cause cracking and other damage to stone. This characteristic has allowed ancient structures like Roman aqueducts and medieval castles to survive for centuries. Durable stone materials continue to be the cornerstone of long-lasting architectural projects today.
Strength
Due to its durability and weight, stone is the strongest material used in the construction world. Structures made with a high percentage of stone last hundreds of years or longer and are capable of withstanding severe weathering and earthquakes.
The exceptional strength of stone allows it to bear immense loads, making it indispensable for foundations, support columns, and monumental arches. This unmatched strength has enabled architects to design towering cathedrals, resilient fortresses, and iconic temples that have stood the test of time.
Hardness
Another useful characteristic is stone’s hardness which again is due to its high compactness and enables the stone to resist damage from scratching or chipping. This quality gives stone a brand-new appearance years after it is built.
Harder stones like granite and quartzite are particularly resistant to wear and are often used in high-traffic areas such as flooring, staircases, and facades. The long-lasting appearance of stone makes it one of the most reliable materials for both decorative and structural applications in historic buildings.
Porosity
Stones should not be porous, since water and other liquids can seep in and cause the stone to expand and crack. Low porosity results in little absorption and therefore lasting and sturdy historic structures. Denser stones, such as slate and granite, are known for their low porosity, making them resistant to moisture damage and suitable for exterior applications. More porous stones like limestone may require sealing treatments to maintain their structural integrity in harsh environments.
Resistance
Stone is also highly resistant to fire and electricity due to its compactness. This immensely adds to its lasting value and durability. Unlike wood or metal, stone does not burn, warp, or conduct electricity, making it a safer material for long-term construction. Its ability to resist heat and electrical conductivity enhances its safety in the event of fires or lightning strikes. This resistance, combined with high compression strength, has helped preserve countless historic buildings through disasters like fires and storms, proving that stone’s resilience goes beyond its physical appearance.
Granite (shown left) has a much lower porosity than marble (shown right).
Types of Building Stone Used Throughout History
Limestone: Valued for its softness and ease of carving, limestone has been a go-to material for decorative elements like columns and façades. Iconic examples include the Great Pyramids of Giza and the U.S. Capitol. While durable, it is susceptible to weathering in acidic environments.
Sandstone: Known for its strength and earthy tones, sandstone has been used in castles, bridges, and temples. Its layered appearance is visually appealing, though its porous nature makes it prone to water absorption.
Granite: Renowned for its strength and resistance to weathering, granite is a staple in monuments and memorials, such as Mount Rushmore. Its dense composition ensures longevity, while its veining adds aesthetic richness.
Marble: Symbolizing luxury and artistic expression, marble has been used in sculptures and palaces, including the Parthenon. Though prone to scratching and staining, its timeless elegance continues to captivate.
For more detailed information, check out our guide on How to Identify Historic Stone and Marble.
Preserving and Restoring Historic Stonework
Since stone is so valuable in the architecture world, the importance of identifying and caring for historic stone cannot be emphasized enough. Conducting a thorough historic stone analysis is essential to understand the stone’s condition, composition, and potential vulnerabilities. This analysis helps inform the best conservation methods, ensuring that preservation efforts are both effective and sustainable.
A few simple measures taken to conserve or prevent wear and cracking will go a long way and will be worth the time, money, and effort for years to come. John Canning & Co. is highly experienced in cleaning, conserving, and restoring historic stonework. Some examples of our company’s work include the restoration of stone and marble at the Barker Library Dome, MIT as well as St. Mary’s Chapel in Boston which involved removing the surface soot and dirt, carbon stains, and efflorescence without damaging or altering the stone’s appearance or strength.