February 17, 2022
Granite or limestone? These two natural stones products are often compared when homeowners in Columbus and Cincinnati are shopping around for exterior building materials. Granite and limestone are hard, durable, and resistant to cracks and weather, which is why they are widely utilized in residential homes and commercial buildings.
Yet, while both are natural stones, the difference between limestone and granite extends further than their colors.
Limestone is a sedimentary rock composed of calcium carbonate. It makes up roughly 10% of the total volume of all sedimentary rocks on earth and is unique due to its composition of fossilized shell-producing and coral-building organisms. From a geological perspective, limestone formation occurs either in marine waters or during cave formation.
Granite is an igneous rock composed mainly of quartz and feldspar. It is an intrusive rock, meaning it was formed from molten lava deep within the earth’s crust. When it cools, the lava crystallizes under intense pressure and forms rock. Granite is located throughout our planet’s continental crust, most commonly in mountainous areas.
After quarrying, limestone is cut into slabs and blocks of a predetermined size, which are used extensively in the construction of roads, buildings, and decorative monuments. This versatile natural stone is also suitable for use at home as pavers, cladding, and aggregates for fireplaces, kitchens, and bathroom countertops, as well as for water features.
Like limestone, granite has been used since ancient times as a construction, decorative and architectural stone. It's an elegant and hardy material appropriate for a range of interior projects such as countertops, fireplaces, floors, stair treads, and pillars. Homes and buildings with granite features produce impressions of elegance and beauty.
The academic, geological definition of limestone classifies sedimentary rock consisting of at least 50% calcite and dolomite, with less than 50% other rock materials as limestone. However, the commercial definition of the stone stipulates the rock must consist of 80% calcite and dolomite, with less than 20% other rock materials. Hence, commercial-grade limestone is stronger and less susceptible to degradation.
How is granite different from limestone? Granite is primarily made from quartz, orthoclase, Microline, and mica and is not fossilized material. Its mineral composition is typically 20-60% quartz and feldspar. Many rocks can be classified as granite due to their mineral composition. However, the commercial definition of granite refers to rock with visible interlocking grains that make it harder than marble.
Granite contains large, coarse grains visible to the human eye. Its mineral composition gives it a red, pink, gray, or white color, with darker mineral grains usually visible throughout. This igneous rock may display flecks and veins, from small lines to large sweeping veins. Granite is named after its “granular” texture, which is easy to spot, even though it can be polished to a brilliant shine.
Upon close inspection, you can usually see fossil fragments, like bits of shell in limestone. Its color ranges from white to gray to tan or taupe. Limestone rich in organic matter may even be black, while the presence of iron or manganese can give it a yellow to red color. It is a softer rock, susceptible to being scratched, and will effervesce in acid.
Granite and limestone strength is relatively high, and neither should need to be replaced during your lifetime. However, compared to granite, limestone does tend to scratch more easily and is susceptible to wear and tear and chipping.
In terms of heat, limestone has stronger absorption capabilities, while granite is better at conduction. Ultimately, both natural stones are strong, and it comes down to project application. Granite is great for countertops, and limestone is possibly a better choice for exterior cladding.
Limestone is mostly formed in the shallow, calm, and warm marine waters of the Caribbean Sea, Indian Ocean, Persian Gulf, and the Gulf of Mexico, where shells and other items build up over time and compact into large deposits. Limestone derived from caves comes from all around the world, with some of the biggest quarries right here in the US. This natural rock is extracted either by blasting or mechanical excavation.
Granite is quarried from all over and takes on the visual characteristics of the minerals most prevalent in the region it's from. For example, Brazilian granite tends to be more pink and blue. The main suppliers of commercial granite are Brazil, China, India, Spain, Italy, and North America. A special saw called a slab saw is used to cut granite. It can take as long as a few hours to a whole day to cut a single slab.
Are you searching for granite, limestone, or other natural stone stockists? Stone Center is a leading fabricator and supplier of superior-quality natural stone. We’re always happy to offer free expert advice, quotations, and recommendations to ensure you’re satisfied with your project. We have an excellent range of natural stone products. Why not take a look and contact us?