Stone is Quarried & Processed

Quarrying natural stone and installing it in someone’s home is an incredibly long and arduous process. Removing a 40,000-pound block of stone from the earth and turning it into a handcrafted countertop or gleaming marble floor is not easy. There are many steps and intricate details which cannot be overlooked in order for a piece of stone to find the perfect setting where it will look beautiful for years to come.

The first step to finding the perfect slab is finding an optimal deposit of material with desirable color, pattern, and composition. This requires geologists to look for stone outcrops which are more easily examined since the bedrock is exposed. Samples are then obtained by boring into the earth to take core samples with expensive diamond-tipped drill bits. These samples are then tested to determine if the stone is suitable for use as dimensional building stone. Later they are polished so that their color and pattern can be examined to determine marketability.

It takes lots of experience, vision and hard work to bring a quarry into full production. A good quarry manager is able to control how to material is removed based on the veining and coloration within the deposit. The manager must have the vision to see how the stone "flows" through the quarry. The same stone can take on many different looks just based on how the block is cut from the wall and later processed. If it is cut with the flow of the source stone, it is called Vein Cut. Vein Cut highlights the movement in the rock. Alternately if the block is cut against the vein, Cross-Cut, it creates a more uniform look for the stone. After the quarry manager decides how to extract the blocks, the drilling can begin. The process starts by taking down a “bench wall,” a large dimensional chunk of rock that is then cut into smaller blocks which will eventually be sent to the factory for processing. The bench walls are cut using a combination of diamond wire cables, drills and even high temperature torches that will melt the stone. Dirt is pushed up against the base of the wall to cushion the fall, and small dynamite charges jar the wall loose to bring it down to a horizontal position. The blocks can then be drilled from the bench wall. Blocks of a given type of stone usually have a fairly uniform size, due to the size of the processing equipment used. Granite blocks usually weigh between 38-42,000 pounds, while lighter marble and travertine blocks weigh between 15-25,000 pounds.


After slabs are cut on the gang saw, they are moved one at a time to the polishing line, where they are laid horizontally on a large conveyer type line called a polishing line. There, they pass under polishing heads which begin with very coarse diamond abrasives, and then move to finer and finer grit abrasives, just like sanding wood. Travertine slabs and some marbles, will receive a cementicous or epoxy compound to fill the natural voids of the stone. Part of the way through this line, slabs of granite, marble, and onyx will receive a coating of a resin treatment which will fill in any pits or micro fissures which are inherent to the stone in order to make the final surface easier to clean. Most of the excess resin is removed by further polishing, with only 1% remaining on the finished surface. For materials where the final surface is to be honed, the process will stop with a lower grit abrasive than materials with a polished surface.

Sealing Natural Stone

Sealing natural stone is a simple process that prevents staining and maintains stone's beauty. We recommend an impregnating sealer which penetrates the stone’s surface to protect it against moisture, dirt, and stains. Before sealing, a thorough cleaning is recommended to avoid sealing dirt and grease into the stone. The life of the sealer will depend upon the type and finish of the stone, the area of application, and its exposure to wear. A piece of stone which is sealed with an impregnating sealer and put in a closet will stay sealed indefinitely. Impregnating sealers are preferred to topical sealers because they increase both the longevity and quality of the protection. Although sealer makes the stone less susceptible to staining, applying when it is unnecessary just wastes time, effort, and money. A simple test to determine if your stone needs to be resealed is to sprinkle it with water. If the water beads up tightly, then the stone has maintained its seal. If the water soaks in or darkens the stone, then allow the water to evaporate and reseal. Granite sealers can last up to 15 years, depending porousity and type of granite. General recommendations for residential flooring is to seal once every 5-10 years. Prior to sealing, clean your natural stone thoroughly with warm water and Mira Clean. Let the stone dry, and then begin working in sections. Apply the impregnating sealer using a clean towel, wiping on a thin coat on your stone evenly covering the entire surface with sealer. Allow the sealer to stand for approximately three to five minutes. Remove excess sealer by buffing with a clean dry towel. If the sealer actually dries on the surface, rewet with more sealer, and wipe dry with a clean terry cloth. Upon completion, wait 24 hours and repeat the water test. If the water beads up, you are finished sealing. If the water does not bead up, apply another coat of sealer

The process of sealing stone is straightforward and can usually be handled by a homeowner as part of normal home maintenance. Sealing a kitchen countertop will take about 30 minutes, but a large area of flooring can take considerably more time. If you prefer, contractors and restoration companies can take care of cleaning and sealing for you.

The "Water test": Here you see unsealed granite on the left where the water is soaking in and darkening the stone. The stone on the left needs to be sealed. Compare this to the sealed granite on the right where the water droplets create beads which sit on top on the stone. The stone on the right is already sealed.

Marble, Travertine, Limestone, & Onyx

Marble, travertine, limestone and onyx are beautiful natural stones that offer unique patterns and colors found in no other materials. Because of their chemical composition, the basic care for these stones is the same. Marble, travertine and limestone are practical for bathrooms, fireplaces and most flooring. Onyx is the jewel and the most fragile of these, and should therefore be used only in low traffic areas. It is important to use good judgment on where to use these calcium based stones because they are susceptible to acid etching. Etching occurs when acids microscopically eat away at the surface of the stone, and are characterized by dull spots in the surface of the material. This effect can be visually minimized by using a honed surface instead of a polished surface. Any spills that occur should be wiped up immediately. For centuries marble countertops have epitomized elegance and the patina that is created with time tells stories of meals enjoyed with family and friends. Sealing: The proper sealant for these materials is Miracle’s 511 Porous Plus. The stones should be sealed immediately after installation. See the sealing application for additional details. Daily Countertop Cleaning: Miracle’s Counter Kleen and Mira Clean are wonderful cleaners for all tops. Clean all spills quickly, especially acidic liquid, because they can etch into the stone’s surface. Place all hot cooking pans on trivets or placemats. Stain Removal: A well- sealed stone is very stain resistant. However, if a stain does occur, it may be removed using Miracle Sealant’s Poultice Plus powder or Liquid Poultice.

Slate & Quartzite

Slate has a unique look, and is an extraordinary and versatile material. Slate has very low porosity that makes it stain resistant and easy to maintain. However, the natural clefts of slate does make its care slightly different than a smooth surface. At Global Granite & Marble, we strongly encourage sealing naturally cleft slate both pre- and post-grouting to make removal of excess grout easier. Quartzite can be clefted like slate, or can be smooth and more similar to marble and granite in appearance. The major difference between slate and quartzite is quartzite’s ability to withstand many freeze-thaw cycles. While quartzite that looks like slate is also cleaned like slate, polished quartzite that looks like marble or granite is cleaned and treated like granite. Slate and Quartzite are sealed and cleaned in the same manner. Sealing: The proper sealant for these materials is Miracle’s 511 Porous Plus. The water test will determine if your stone needs to be sealed. Daily Countertop Cleaning: Miracle’s Counter Kleen is recommended for slate and quartzite tops. Cleaning of Floors and Walls: We recommend Mira Soap to clean slate and quartzite walls or floors.