Stone comes from Mother Nature. Natural stone, both beautiful and durable, is one of the oldest and most dramatic elements found in architecture. Today there are many more types of stone available in both slab and tile form than here were just a few years ago. While it has become an increasing popular material in new homes, it is important to maintain a balance between the beauty and vitality of natural stone and its appropriateness.
One of the first things to consider is how the material will be utilized. The two most important considerations are the hardness of the stone, and the absorbency of the stone. All natural stones are porous to varying degrees. Degree of hardness, durability and resistance to acid, stain and water are important aspects to keep in mind. Unlike ceramic tile, most natural materials must be maintained. In many cases, natural stone is not as hard as a glazed tile, which has been fired in a kiln. Some stones may lose a degree of color due to ultraviolet rays in the sunlight.
There are two forms of maintenance, daily and periodic. Daily dust mopping will keep surfaces free of dust, grit and sand. Wiping down shower walls and countertops immediately after usage is recommended to keep water spots, food stains and dirt from accumulating. Periodic maintenance includes the application of an impregnator or sealer on an annual basis. It is important to use the same sealer with each application, as some chemicals will not mix.
Granites are typically the hardest of the dimensional stones. They are great for kitchen countertops since they resist scratching, are stain resistant and heat resistant. Granite is also suitable for flooring and wall cladding and can be used in both interior and exterior settings.
Limestone is most common in a “honed” finish (a smooth surface with little or no gloss.) The surface may have rough areas, which are common on some types of stone. Limestone densities can vary, ranging from that of marble to that of granite. It, too, is suitable for interior or exterior use.
Marbles may be highly polished or non-reflective. They are basically limestone that has been subjected to heat and pressure. In all but the lightest traffic areas, a honed or textured marble is recommended because of the labor and expense in maintaining polished surfaces in abrasive areas. Polished marble may be maintained by the use of some sort of sacrificial barrier (a heavy coat of sealer or coating) on top of the stone. Like granite and limestone, marbles can be appropriate for interiors and exteriors.
Most of the flagstone used for residential applications in New Mexico is sandstone or quartzite. Since most of these stones are taken from the ground in individual layers, they are typically used as flooring or paving materials. Most have a “natural cleft” finish, meaning the finished surface is the way the stone came out of the ground. Some sandstones are honed for a smoother finish. Most flagstone lends itself to interior or exterior use.
Slates are relatively dense. They are a natural cleft material and are typically used for flooring or roofing. Most slates are acid and stain resistant. Dark slate will typically have a wider variation in color. Slate is very suitable for interior and exterior applications.
There are many new and different stone materials. Many have a “tumbled” or honed finish and are referred to as tumbled stones. These are usually in a four-inch square size and used as a decorative accent or surface application. Care must be taken to understand the properties each individual material and how it should be maintained.
Cultured stone has become a very attractive alternative to natural stone. It is usually a lightweight concrete material made in forms. The forms are created from real stone. Surprisingly realistic, cultured stone comes in an amazing variety of styles of colors and provides an appealing alternative to the expense of natural stone. Like most natural stone, it is a good veneer for both interior and exterior use.
With the right choice of materials and appropriate application, natural and cultured stone can provide homeowners a lifetime of beautiful and durable use.
Special thanks to Rocky Mountain Stone, Design Materials Inc. and Architectural Surfaces for helping with this article.