How Marble and Granite Countertops Are Made

Marble and granite countertops can complete the appearance of a new kitchen. If you’re looking into different types of countertops, you may be curious about the process that goes into creating them. We detail how marble and granite countertops are made in this post to satiate your interest.

Cutting Out Blocks

First, workers must collect stone from a quarry. These may be within the United States or in other countries from which the granite or marble will be imported. At the site of a quarry, the desired stone is usually initially inaccessible. Workers must use large pieces of equipment to dig into and remove the top layer of soil that covers the stone, called the overburden. Once they’ve accomplished this, they break away parts of the stone they don’t want using drills and sometimes by blasting away sections.

With the marble or granite ready for harvesting, workers drill holes into the top of the rock and then thread a wire saw through them, which has pieces of diamond attached to it. The saw grinds the diamonds against the stone, cutting it into a massive block.

Dividing Blocks into Slabs

While still at the quarry, that block of stone is cut further into slabs with gang saws. Gang saws have multiple rows of blades or wires that cut the block simultaneously and evenly. Workers use higher-precision bridge saws on each of these slabs to cut them into the proper shapes for the countertops they’ll become. Bridge saws use blades or wires, and newer models spray high-pressure water to make cuts.

Afterward, one face of the slab receives a polishing from machines with abrasive extensions that grind down the stone to make it smooth. Workers may set the polisher machine to create different finishes, including polished (shiny and reflective) or honed (smooth but matte). Once the polishing is complete, the slabs are ready to be packed and shipped to the businesses that supply granite and marble to countertop fabricators. Slabs from one block of stone are usually packed together to allow buyers to get more than one piece of countertop in the same exact pattern and color.

Forming the Countertops

Next, the countertop fabricator visits the warehouse where the stone is offered and pick out what they need based on their own preferences, a designer’s direction, or a customer’s preference. Work on the countertop cannot start unless the cabinets onto which they’ll be installed are complete.

Once they’re able to proceed, the countertop fabricator mostly utilize computer numerical control (CNC) machines to digitally detail the dimensions they want. They have the CNC machines cut the slab based on the directions they input in the software to achieve high precision. With the final shape cut, the fabricator uses edge polisher machines to create a finish on the sides of the countertop that match that of the top face.

image credit: twenty20.com