Limestone is a well-known type of stone that may refer to a number of different stone formations made with the same main component: calcium carbonate. True limestone naturally forms when springs and other bodies of water precipitate, leaving behind calcium-like minerals that eventually layer into limestone.
Over the years, limestone has been used mostly for construction and building processes as aggregate in concrete, pulverized with resins to create engineered stone, and more. However, the stone has also been used for tiles, walls, and as heat-resistant countertops.
A stone must have at least 50% calcium carbonate composition to be considered limestone. The porosity and density of limestone varies depending on the different minerals that comprise the stone, and the coloration is dependent on its chemical composition.
Limestone is known to contain fossilized materials within its formation, and these fossilized remains are from prehistoric plants and fauna that eventually turn into sedimentary rocks, giving us a glimpse into the lives of the natural, prehistoric world. Fossilized limestones would typically have imprints of animal bones, shells, and sometimes plant veining.
Limestone can come in multiple colors from white to beige, and even shades of green depending on the composition of minerals in the stone. The most common hues of the stone would range between a cream to gray color, but gold varieties also exist. There are also peach, yellow, and blue-gray shades that can be used for decorative purposes.
The texture of limestone is similar to that of concrete, as the stone is incredibly porous. Its porosity lends the stone a rough texture and a decreased hardness compared to other stones like granite and slate. Raw limestone may have a powdery feel due to the dissolved minerals surrounding the stones.
The fossilized organisms in limestone can create natural-looking patterns with a niche aesthetic of prehistoric shells, plants, and skeletons. The vast majority of fossils in limestone are from marine organisms like sea snails, coral, and more; adding to the under-the-sea appearance of the stone.
Beneficial Features of Limestone
One of the sought-after benefits of limestone is the stone’s resistance to heat. As kitchen countertops, the stone can be safely used in food preparation, and takes no damage from hot pots and pans set on the stone. However, the stone is relatively soft and porous, so limestone countertops will typically have a penetrating sealant to keep the surface clean.
When used as a construction material, limestone becomes an ingredient that strengthens mixtures like cement and concrete. Limestones used in cement mixtures are often made up of low-grade limestone, which has a higher concentration of clay. During the hydration process, limestone undergoes a chemical reaction that results in a hardened material once dried.
Uses of Limestone
The main use of limestone is in construction as an aggregate material for concrete structures. The use of limestone in industrial settings is common practice, as the stone is easy to process and pulverize into the materials needed. The majority of concrete materials will contain limestone, or limestone-like ingredients, with the exception of eco-concrete.
Limestone may also be used as flooring, wall tiles, and countertops, but will need a strong, penetrating sealant to protect the stone against wear and tear, and to prevent stains from setting into the stone. Limestone may also be used to create decorative pieces, particularly with limestone formations that have clear fossil patterns on them.
Limestone is a high maintenance material when used as a countertop, tile, or flooring. Due to its high calcium carbonate content, acidic solutions will easily dissolve limestone, and a bubbling reaction will occur when an acidic solution is applied directly on the surface. For this reason, it is recommended to seal limestone with a penetrating varnish to protect the stone from damage.
Moisture can also seep into the pores of the stone, especially when left unsealed. The soft stone tends to scratch easily, so avoid using abrasive cleaning tools to scrub the surface. As tiles, limestone should be sealed along with the grout to prevent damage from moisture and oils.