Marble countertops undergo several processes before they are ready for use. Here is a basic outline of how marble countertops are made.
Transport of raw materials
Moving a large piece of marble is not as simple as loading it onto a truck bed and hauling it away. Each piece must be treated with care to protect it from the bumps and falls they may incur during transport. Large trailer containers are usually packed with raw rock, and gaps in the corners and borders of the container are fitted with molded rubber foam. This locks the marble slabs in place and prevents them from moving and smashing into each other while on the road.
Once the raw material arrives at the shop or factory, the rocks are gently removed with special cranes and winches. This is usually a slow, laborious process, because marble slabs are very fragile and must be handled with great care. Marble is a very expensive material, and every bit of it must be saved to avoid wasting a great deal of money and time.
Cutting and water-blasting
Rocks usually arrive in large chunks and must be cut into reasonable sizes to make them usable. This is done with large, computer-operated saws, since rock is too hard for common hand saws. Also, cutting marble countertops requires a level of precision that humans are simply incapable of.
Once the piece has been cut into slabs, most are further cut into squares, creating the initial shape of a marble tile. While these are unfinished products, most people would readily recognize them. Slabs more than an inch thick are prepared for installation as solid marble countertops and are delivered uncut.
After being cut, each tile is blasted with a powerful water jet, which smoothes away any imperfections around the tile’s edges and surface. The water is sprayed at over 200 miles per hour and is kept at pressures exceeding 70 pounds per square inch (psi). At this speed and pressure, the water spray can cause serious injuries, so most masons stand behind safety glass walls during blasting.
Finishing and detailing
After the tiles are cut and water-blasted, they are ready to be finished and detailed. Finishing involves buffing the pieces repeatedly with varying grades of sandpaper. The initial buffing comes from coarse sandpaper, with the coarseness gradually declining with each phase of buffing. Finally, the pieces are ready to be polished and detailed. Polishing creates the mirror-like finish that marble is valued for.
Some people like having their marble pieces customized, and most manufacturers have highly skilled masons on hand to work details into the marble. Border tiles and edge coverings are usually worked with intricate geometric designs, giving the finished product more uniqueness and character.