Natural Stone Types and Granite Countertops

There are many different types of natural stones in the world and each has their own unique beauty, characteristics and applications for use. We have been able to identify some of the more popular stone types along with their properties, advantages and disadvantages and the most suitable usage in your home.

There are three different types of stones; Igneous, Metamorphic and Sedimentary. The Igneous stone is formed by cooling, or solid-state transformation of molten or semi-molten material in the Earth’s upper mantle or crust. Because it is formed under extreme pressure and high heat, this type of stone or rock tends to be very strong and dense. The Metamorphic stone is formed from any preexisting rock type in the Earth’s crust under variable conditions of high pressures, high temperatures, chemistry, and time. This process produces mechanically deformed stone and chemically altered the mineral assemblages of the parent stone. Metamorphic stones tend to be some of the most beautiful, colorful, and highly figured of any of the dimensional stones. Note that many of the metamorphic stones are up to 3.8 billion years old.

The last being the sedimentary stone which falls into one of two categories: Detrital sedimentary stone and chemical sedimentary stone. Detrital stone is the naturally cemented accumulation of solid granular particles or materials derived from both mechanical and chemical weathering of any existing rock. Examples include limestone and sandstone.

Limestone and Sandstone can both be used for fireplaces, vanities, flooring and furniture. They are very soft, porous, scratch and require maintenance. Sandstone has a very rustic look with fossils while Limestone has a very unique look & feel, and is also available in multiple finishes. Limestone has actually become quite popular for kitchens.

Chemical sedimentary stone is formed from the precipitates of chemicals like salt that are the dissolved weathering products of any existing stone. Chemical weathering yields soluble salts that in turn are deposited into pools and springs. This process yields stone such as onyx and certain Travertine. Onyx has a translucent and stunning appearance, scratches very easily and is quite soft. Onyx can be used for furniture, architectural & design elements, fireplaces and for powder rooms. Travertine has a cloudy formation when cross cut it gives it a more unique look, it is softer than marble and limestone, and it has many larger voids and stains. Travertine is suitable for vanities, floors, fireplaces and dryer locations.

Granite is an example of an igneous rock; it has a very high concentration of quartz, making it very hard and difficult to scratch. It is heat resistant (under 1,500 Fahrenheit), stain resistant and impervious to acids. There are extraordinary selections and finishes of granites available. It can be used anywhere; kitchens, floors, wet/dry, and for indoor and outdoor applications.

Quartzite is another example of an extremely hard stone yet classified as a metamorphic stone; it is one of the hardest stones used in commercial applications.It was originally formed from sandstone, quartzite generally is found in muted earth tones: grays, whites, browns, and yellows. It is very hard, dense and acid resistant. It is harder than granite and has exceptionally low moisture absorption; it is suitable in any application, though cost may be a consideration.

Another example of a metamorphic stone is Soapstone. It is one of the most unusual stones used in the commercial market today. Soapstone is soft and carveable and is resistant to acid. It is also one of the most popular stones used in kitchens today. Soapstone is an excellent choice for fireplaces surrounds as it absorbs and releases heat evenly. In order to keep it looking dark and vibrant, it is recommended that countertops be treated with mineral oil every six months.

Marble is also a metamorphic stone, it is classic with an “old world” look, it develops character with age. It is porous, scratches, stains, etches and requires care and maintenance. Marble can be used for vanities, fireplaces, furniture tops and kitchen countertops as well if honed. Serpentine although most closely related to marble, is technically not a “true marble,” it is by definition a metamorphic limestone. Often called a “green marble,” serpentine is usually dark green with white veining. This look is sought in luxury bathrooms and grand entrances alike. It is a relatively hard stone and does not scratch as easily as a “true marble.” It is acid and scratch-resistant making it a great choice for kitchen countertops. Other applications are floors, vanities and any dry locations; it is not good for showers or for any other wet applications as it could tend to warp over time.

Slate is another metamorphic stone that has been used as a durable roofing material for years. It generally comes in dark gray shades with hues of blue, purple, green and brown. Slates hardness varies significantly. Softer slates are best used for flooring and non-stressed architectural elements, like fireplaces. It can also be used for counters and vanities. It is rustic, stain resistant except for oils and does requires maintenance.

It is very important when considering a project, to ensure that the right material is used for the application. Every stone has specific characteristics. Using the wrong stone in an application can lead to material failure, damage, or other conditions. Knowing which stone to use in an application only comes from years of experience and you should always consult with an experienced stone professional.