How Are Granite Countertops Made?

Granite countertops are one of the most popular home features around. The attractive and easy-to-clean surface has a broad appeal that’s spanned decades.

If you turn on any real estate or home improvement show, you’re sure to see people dead set on granite surfaces in their kitchen. Chances are slimmer that you’ll see anyone on those shows ask “How are granite countertops made?”

This article here is to fill in what real estate shows leave out. Here’s all you need to know about how to make granite countertops, all the way from the very beginning.

How Does Granite Form?

You can’t have granite countertops without granite, and it all begins deep underground. Granite forms from magma, so it’s a kind of igneous rock. The magma flows up towards the surface of the earth, then crystallizes as it cools over a long period underground.

Due to the slow cooling process, the crystals that form are large. They give granite its signature look.

The reason granite comes in a variety of colors is because various granite deposits have different mineral compositions. Quartz, potassium feldspar and sodium feldspar provide common white-to-pink and gray tones. Brown and black come from biotite, black and green come from amphibole, and yellow comes from muscovite.

What’s the Process of Mining Granite Stone?

Before fabricators cut granite into slabs, countertops, and tiles, it has to come out of the ground.

Miners harvest white and gray granites in the United States. There’s so much granite in New Hampshire that it earned the nickname “the Granite State.” There’s a lot of granite in Indiana, Texas, Wisconsin, and Georgia, too.

Construction companies use white and gray granite mined in the USA, and so do manufacturers of things like monuments and gravestones. Those kinds of granite are somewhat basic for most homeowners’ tastes. More exciting colors and patterns popular for kitchen countertops hail from Brazil and India. 

At the quarry, miners drill holes according to specified dimensions—often as big as 10′ wide. Then, they take care to place explosives in the holes. They break the block from the surrounding bedrock without cracking the block. They use a cushion of sand to keep the stone from splitting as it falls from the bedrock.

How Are Granite Countertops Made From Stone Blocks?

It’s typical for quarries to have a processing factory on-site. This factory cuts the granite blocks into slabs, the middle step between block and countertop. Most slabs are around 2 or 3 cm thick.

What Tools Cut Granite?

It takes strong tools to cut stone. In fact, cutters use one of the strongest materials on Earth to slice granite slabs: diamonds.

Diamond wire saws take their time slicing through the blocks for precise results. Some quarries use these saws instead of explosives when mining the initial, raw blocks.

Because it takes hours to cut a slab of granite, quarries use gang saws—saws with multiple blades or wires—to cut several slabs at one time.

What’s Used to Polish Granite?

Once the fabricator cuts a granite block into slabs, the factory polishes each slab using more diamonds embedded in pads. Each pad is finer than the last to get the most shine possible.

The polishing process only treats the top of the slab. The edges are still rough, so the slab has a long way to go before it’s suited for home use.

Some granite isn’t polished. Honed granite has a tamed shine, and water jets give leathered granite its unique texture. Local fabricators apply these other finishes.

How Does Granite Get to Fabricators?

Once the quarry cuts and polishes the granite slabs, they’re ready for shipping. Much like panes of glass, movers load the slabs on their edges so they don’t break when traveling over bumpy roads. They’re sent overseas on cargo ships and cross-country on trucks to warehouses all over the United States.

Fabricators consult with customers to determine their needs and help them choose a slab. Depending on the operation, clients might pick a sample tile and let the fabricator choose slabs, or they may go with the fabricator to the warehouse to pick the slabs themselves.

Once the local stone fabricators have their customers’ chosen slabs, they’re ready to cut custom pieces.

How Do You Measure for a Granite Countertop?

There are endless creative kitchen layouts and countertop designs. Every kitchen has its quirks, so stone fabricators don’t pre-cut granite countertops according to some standard model. They design and cut a unique counter for every kitchen.

Installing a granite countertop is too technical of work for customers to do their own measurements. Fabricators send technicians to clients’ homes to measure their cabinets.

Digital templating tools ensure precise measurements so that fabricators do the job right from the outset. These visits also provide a chance for fabricators to get measurements for sinks and other features that need cutouts.

How Are Granite Countertops Cut to Size?

With the client’s chosen granite slab and the desired measurements in hand, the fabricator can get to work transforming the granite slab into a countertop. Accurate cutting is no obstacle with computer numerical control (CNC) cutting machines.

CNC routers allow fabricators to enter measurements for a countertop into a computer that directs the cutting process. Using a CNC machine reduces human error in measurement and cutting as much as possible. 

As in other stages of the production process, diamond wire cutters are the tool of choice for precise stonecutting. Water used in the cutting process reduces friction and heat. In some cases, a water jet is itself used as a stonecutting tool.

The cutting process replaces the slab’s rough edges with smooth and elegant countertop edging. Smooth edges are important both for aesthetics as well as for safety.

After the manufacturer cuts a granite countertop, it’s inspected for quality control. Craftspeople make any needed small changes to the countertop before sending it out for installation.

What Can You Do to Get Ready for Granite Countertop Installation?

Nobody planning for their first granite countertop pictures what the installation looks like. With so many unknowns, waiting for installation may be anxiety-inducing. There are a few things homeowners should do in the meantime to make sure they end up with the best granite countertops.

Finish and level cabinets before countertop installation. Make sure there’s a wide-open path for installers with enough room for any needed pivoting. Little things like cleaning sawdust away from an installation site go a long way in ensuring installation success.

If you’re replacing countertops, it’s a good idea to have the old counters removed for more accurate measuring.

How Do Granite Countertops Get to Homes?

Like the original slabs, countertops traveling to houses from the factory rest on their sides. Even weight distribution reduces the risk of cracks in the final leg of the journey.

Fabricators transporting granite countertops use wooden A-frames to support the stone on the way to the client’s house.

How Is a Granite Countertop Installed?

Large granite countertops weigh hundreds of pounds, and a single person should install none but the smallest granite countertops alone. Fabricators deliver large countertops with at least a couple of people.

A granite countertop stays vertical as installers carry it from the vehicle into the house. It’s laid flat at its destination, and stonecutters make any holes for sinks and faucets. They have to drill and cut these holes in place because trying to move granite with holes cut in it leads to cracks.

What Are the Final Steps?

After installing a granite countertop, it might not yet be ready to use. Granite is a somewhat porous stone and so you have to seal it. This is the finish to any granite countertop.

Most fabricators seal granite countertops before installing them, so your new countertop may be ready to go. You can test the seal by spraying a corner of the countertop with water and seeing if it soaks in. Also, test the counter with a little bit of oil.

If the water and oil stay on top of the counter, it has an intact seal. Don’t add more sealant to a sealed countertop or you’ll cover the counter with an ugly film.

However, you should test your countertop’s seal again six months or so after installation. Different kinds of sealants have different lifespans, but you need to reapply all of them in time. Some last for years while others last for less than a year.

If you need to reseal your counter after six months, consider applying a long-lasting sealant so you don’t have to repeat the job for a good while.

Do You Want Your Very Own Granite Countertop?

After reading this article, you’re an expert on granite countertops. Now you can answer the question you asked before—How are granite countertops made?

Some more questions for you: Do you live in Chesterfield, Kirkwood, O’Fallon, St. Charles, St. Louis, St. Peters, or Wentzville, Missouri?

Are you looking for a countertop made of granite or another stone, or stone for another home feature?

If you answered yes, get in touch with Rock Solid Creations to set up a free stone consultation or with any other questions.