Glossary of Natural Stone Finishes

Let’s Talk About Natural Stone Finishes

Natural stone comes finished in many ways. It doesn’t start that way from the quarry and it doesn’t always have to stay the way it is after it is installed.

The appearance of all natural stone is rough when it is first quarried. The surface is then altered to any number of finishes. (The name of the finish often explains how the finish is produced.) When selecting stone, understanding your options will help you to choose the best finish for the look you are going for and for your intended use.

Fabricators and stone suppliers almost always purchase stone that is already finished, so when you purchase new stone for an installation, the finish you see is the finish you get. Most of the time.

Professional stone refinishing can often alter the finish of stone using various methods, even after it is installed.

With this in mind, the following glossary of finishes will help you understand natural stone finishes, which ones are best for various purposes, and what options you have to change certain finishes.

Your Finish Options

Following is an overview of the most popular finishes, how they are achieved, and where they are most appropriate.

Polished

Natural stone with a polished finish has a glossy, mirror-like quality that showcases the colors, veining, and other unique characteristics of natural stone. If your highest concern is that the stone has an elegant appearance, a polished finish is a good choice. A polish can be achieved by using a specialized abrasive technique. Diamond-infused pads mounted on a machine rub against the stone, similar to sandpaper on wood. Industry professionals describe this process as honing and polishing. Progressively finer grit pads are used until a highly reflective polish is achieved. Polished finishes may not be slip resistant and are most appropriate where a slip and fall hazard is not a concern.

Honed, Satin, or Matte

Natural stone with a honed finish is softer and velvetier in appearance than a polished finish. The words honed, satin, matte and other descriptive terms are used interchangeably to describe a finish that is not as reflective as a highly polished finish. A honed finish can be created using the same specialized abrasive technique as that of polished stone, except that the level of desired polish is achieved sooner, with less polishing. Honed finishes are often requested where slip resistance is desired, however, a honed finish is not a guarantee that the surface will be slip resistant. Some stones are slippery even when honed.

Brushed / Antiqued

If a textured look but a smooth touch is desired, a brushed finish, also known as an antiqued finish, may be a perfect option. This type of finish is achieved using wire wheels and brushes that create thousands of microscopic scratches. The end result is a natural stone finish that looks like it has beautifully and uniformly aged over centuries of time and use. A brushed finish is an excellent choice in a setting where slip resistance and ease of maintenance is desired. Most brushed finishes will be a little more difficult to clean than honed or polished finishes.

Textured / Hammered / Tooled

Unlike smooth honed and polished finishes, textured finishes, also known as hammered or tooled finishes, have varying degrees of roughness, depending on the methods used to fashion the texture. For example, a flame heats the surface of granite to create a flamed finish. With a sandblasted finish, abrasive media is sprayed under high pressure across the surface of the stone. A tool that looks like a meat tenderizing hammer is pounded on stone to create the pockets and ridges of a bush hammered finish. With a cleft finish, the stone is simply split, and the naturally uneven break is the finish. Textured finishes hide imperfections and camouflage minor surface damage like scratches and etching, so they are ideal for areas with excessive traffic. Textured finishes are not ideal for countertops or surfaces that need to be cleaned often, because the uneven surface will snag sponges and cleaning cloths. These finished are most appropriate for exterior stone installations such as sidewalks and pool decks.

Custom

A combination of finishes may be used on a single stone surface to achieve a custom finish. For example, a logo or pattern can be sandblasted onto polished stone by protecting certain polished areas and sandblasting other areas. A similar process might involve applying acid to stone that contains calcium carbonate, causing chemical reactions that will roughen the surface of the stone. A custom finish is a great option for creating a focal point or showcasing a natural stone feature.

Impregnators, Enhancers, and Topical Coatings

There are a variety of sealers, coatings, and enhancers available that can also alter the look of stone. Be sure to consult with your PRO as using them may not always be useful or beneficial, and in some cases will result in problems.

Impregnating Sealers

Contrary to popular belief, impregnating sealers do not give stone a shine or change the texture or appearance of stone in any way, except if an impregnating sealer also happens to be an enhancer. Impregnating sealers are designed solely to fill the pores in stone to inhibit spills from staining.

Enhancers

The colors inherent in some natural stones can be heightened and intensified with enhancers. If you desire stone with a wet look (think how the color of jeans darkens when wet), enhancers will achieve this while also offering different levels of shine. Most enhancers do not inhibit staining unless the enhancer is also an impregnating sealer. Enhancers are often considered permanent, because once they are applied, they are extremely difficult to remove, but enhancers do tend to fade or are slowly removed over time with cleaning.

Topical Coatings

Unlike impregnating sealers that penetrate beneath the surface of the stone and don’t affect the look of the stone at all, sealers that stay on the surface of stone are referred to as topical coatings. Although these coatings protect stone against stains, etching, scratches, and other surface damage, they can be problematic. In general, coatings themselves can be damaged, turn yellow, and attract dirt and contaminants. Many topical sealers on floors look great at first, but once the appearance of the coating diminishes, it must be completely stripped and reapplied. Another consideration is that stone on floors needs to breathe. Coatings can trap moisture, resulting in damage to the stone itself, such as cracking, flaking, and spalling. In some situations a topical coating might be suitable, but you will want to consult with your stone restoration PRO to be sure.

Stone Restoration Technicians Can Change Finishes

When all is said and done, if you are not happy with the finish of existing stone floors, countertops and other surfaces, let’s discuss it. We can evaluate your stone and may be able to alter the appearance more to your liking. We routinely refinish shiny, polished stone surfaces to a honed (matte or satin) finish and vice versa, apply decorative textures, enhance colors, and apply specialty treatments.

3 Tips for Comparing Stone Restoration Bids

Choosing a stone restoration contractor by comparing bids based only on price can be a costly mistake. There are other important factors to consider before you make a decision. Here are three tips for comparing stone restoration bids.

1. Does your contractor understand your particular type of stone?

Although there are similarities between marble, granite, travertine, and other types of stone, there are also differences that require specific restoration processes. Janitorial and cleaning companies may provide valuable services but their technicians are rarely properly trained, qualified, or experienced when it comes to natural stone restoration. Even some stone restoration companies may have little or no experience with your specific type of natural stone. Be sure to ask what your prospective contractor knows about your stone. They may offer the cheapest price, but in the wrong hands, your stone could end up with poor quality results or problems such as dimpled or wavy surfaces.

2. Are there hidden costs not included in the bid?

Basic stone restoration involves honing to remove surface damage and polishing to restore the finish of the stone. Your prospective contractor may not have included other procedures necessary to make your stone look brand new again in the bid. For example, does your stone have deep scratches, chips, or cracks? If the bid only includes honing and polishing, the contractor is not legally obligated to do special repair work. Does your stone need to be sealed? If so, check if sealer application is included in the bid.

3. Will the contractor be able to accommodate your schedule?

Scheduling is important for many people, but especially for business owners and property managers. In order to minimize disruption to the normal routines of employees, guests, and patrons, it’s important to know that your contractor can provide a plan of action that includes a start and finish date, and if necessary, work during the least busy hours or make special accommodations, such as keeping sections of flooring open for traffic while they work. Be sure to communicate your needs and confirm these details before accepting a bid.

Once you’ve taken the time to select contractors and gather bids for your stone restoration project, follow these tips to make an informed decision so that you will be happy with the entire experience, not just the price.


This article is one of a series of articles written and published on behalf of Surface Care PROS Partners.

Why Pool Decks Turn Green and Black

Why Pool Decks Turn Green and Black

What is that green and black stuff growing on my pool deck? This is a question pool owners often ask. This article will help you identify and remove pool deck discoloration, as well as minimize the likelihood of future discoloration.

Biological Growth Types

The majority of unsightly green and black spots on pool decks are the result of biological growths in the form of algae, molds, lichens and mosses, and plants such as ivy and grasses. Let’s take a look at each:

  • Algae is commonly green in color but can also be black, orange, red or yellow. It is easy to identify since it grows in mats, films, and patches on the surface of stone, brick and concrete. Algae is a single-cell plant but lacks roots, leaves, stems and vascular tissue. Most algae, especially the green type, needs moisture and sunlight to grow. However, there are species that will grow in damp, low-light areas.
  • Moss is most commonly green but can also be red. Like algae, it requires sunlight and moisture to grow. It also needs a mineral source often found in soils. Unlike algae, moss has a root structure and a very small leaf structure. It will often grow in grout between stone and masonry.
  • Mold is a fungus, not a plant. It does not require sunlight but does require moisture and an organic food source. Mold is generally black in color but can also be red, orange, brown, or yellow. Limestone is especially susceptible to mold growth, since it contains organic matter that can feed mold.
  • Lichens are comprised of a fungus living in a symbiotic relationship with an algae or a relative of bacteria called cyanobacterium (or both in some instances). They can be red, yellow, red, green, or white. Lichens are identified by crusts or leaf-like structures with defined borders growing away from the surface of the stone or masonry.
  • Ivy, grasses, and higher plants are easily identified by their root systems and large leaf structures. They are often green in color.

Removal of Biological Growth

Regardless of the type of biological growth, removal requires the use of biocide cleaning chemicals, such as peroxide, bleach, or other biocides. Here is a basic cleaning procedure that is recommended to remove these growths. Be sure to carefully read the directions on chemicals and take all necessary precautions. Wear gloves and protective clothing. A mask is recommended, since some mold and algae can emit spores that can be harmful to your respiratory system.

Algae is best removed when it is dry since the spores are more likely to become airborne when wet. Allow the surface to fully dry, or expedite the drying process with a fan. Remove as much algae as possible by scraping or scrubbing with a stiff broom or brush.

A pressure washer can be used to remove the remaining biological growth, but there are a few additional precautions and recommendations:

  1. Do not use high pressure. Test the pressure in a non-conspicuous area to make sure you are not damaging the stone or masonry.
  2. Use hot water, if possible. Hot water will kill some of the biological growth and sanitize the surface.
  3. Use a wide nozzle tip to minimize damage. Keep the tip of the wand at least 12 inches away from the surface.
  4. Bleach or vinegar can be used to clean stubborn growth. Mix the bleach or vinegar. Use one cup of bleach or vinegar with one gallon of water. Test this mixture in a non-conspicuous area to see if it will cause discoloration. Some stone and masonry types can lighten, discolor, or etch with bleach or vinegar.
  5. Apply the bleach or vinegar mixture on the deck and allow it to sit for 15-20 minutes. Do not let it dry. (If it accidentally dries, apply more of this mixture.)
  6. Scrub the area with a nylon brush. Rinse with plenty of clean water. Be careful to avoid nearby plants, since this mixture can kill landscaping plants and grasses.

In lieu of bleach or vinegar, you can use many of the commercial cleaners appropriate for your pool deck surface type. You can find them at most home centers. If your pool deck is natural stone, be sure to use a pH-neutral, stone-safe cleaner. Read the directions carefully.

Spot Removal

If you have just a few spots, you can use 3% hydrogen peroxide. Simply spray the growth with the peroxide, allow it to sit for several minutes, and then rinse with water.

Prevention

Your best defense to keep biological growth at bay is to clean the deck on a regular basis. We can professionally clean your pool deck for the best results. We can also apply sealers and preventive biocides to inhibit new growth.

We can provide specific recommendations regarding cleaners for green and black growth on your pool deck.


This article is one of a series of articles written and published on behalf of Surface Care PROS Partners.

I’m sorry, I think you mythunderstood me

It’s kind of funny what people who should know better will say about common stone failures or issues. Over the past several years, we have heard many stories about the reasons stone will fail, turn color, fade, and so on. Many are comical and most are just plain false. Here’s a sampling you may enjoy…

A Warped Sense of Humor

Many seasoned installers who have tried to install green marble tiles with ordinary thin set or other water-based setting materials have experienced warping problems. Here are two ways we’ve heard them explained.

1. Myth: “Green Marble will warp because it contains living plant material. As water is added to the marble, the plants start to grow and this makes the marble warp.” We nearly fell over laughing, but he wasn’t kidding. He really thought this was the reason.

2. Myth: “Green Marble will curl on the edges because the installer did not put enough setting mortar on the edges. The green marble will have a tendency to lift off the floor where there is no mortar and hence will curl.” While not quite as outrageous as the first explanation, it is still just as wrong.
Truth: The real reason green marble warps is a condition known as hysterisis. Green marble is very sensitive to moisture. When water enters the stone, it causes the marble to release any internal stress, thus causing it to warp.

Home Sweet What?

3. Myth: “Your stone floor needs to be homed!”
Truth: No, this is not a spelling mistake – the word used was “homed.” We have run into several sales people who have called the honing process “homing.” Maybe they also worked with pigeons, but we’ve never heard of homing a floor. The proper term, of course, is “HONE,” which means to abrade a stone.

“Plop, Plop, Fizz, Fizz…”

4. Myth: “Your stone floor has an effervescence problem.”
Truth: The key word here is “effervescence.” Let’s clear this up right now. Efflorescence is the deposit of soluble salts on the surface of the stone that is caused by water that carries the salts from the setting bed of the stone to the surface; it is often deposited as a white powder-like residue on the surface of the stone. Effervescence is what happens when something fizzes. A good example is when you drop a tablet of Alka-Seltzer into a glass of water. The fizzing is referred to as “effervescence.” We’ve never seen a stone effervesce unless someone was pouring acid on it!

5. Myth: “Sealing your stone will help with your efflorescence problem.” Truth: We’ve heard so-called experts instruct people with an efflorescence problem to seal the stone as a remedy. This is wrong. Sealing will only block or reduce the pore size of the stone, which will not only cause more efflorescence, but it could also cause spalling, which is when the stone flakes at the surface.

Are You Cracked?

6. Myth: “That’s not a crack, it’s a fissure!”
Truth: Many fabricators will try to blame cracks that occur in stone installations on natural fissures that occur in the stone. Sometimes they are right and sometimes they are wrong. If you look up the word “fissure” in the dictionary, guess what? A fissure is a crack. The distinction they are trying to make is between fissures, which are naturally occurring as part of the formation of the stone and cracks (more appropriately called “breaks”) caused by external forces on the stone. Of course, the most likely place for a break to occur is on a natural fissure. Consequently, definitions need to be clarified and the stone needs to be examined carefully to determine if natural fissures are at risk of becoming breaks during normal usage.

Would You Like Some Salad With That?

7. Myth: “To remove oil from stone, saturating it with water will force the oil out.” Truth: Since it is true that oil floats on water, you would think this makes sense. But trust us, it doesn’t work. The oil is trapped in the pores of the stone and no amount of water is going to force it out. The best way to remove oil from stone is with a poultice and a degreasing chemical. For specifics and poulticing instructions, see https://surfacecarepros.com/stain-management-app/ .

8. Myth: “Just use some vinegar and water to clean your marble or limestone.” Truth: Generally folks in the stone business know better, however this is often recommended by tile installers. Don’t do it! Vinegar is an acid and will etch calcium-based stone. Marble and limestone are generally the most susceptible, but some types of granite will also be damaged by vinegar.

Stones Can Be So Vein!

9. Myth: “If it’s got veins, it’s marble.” Truth: This is a fib we hear all the time. Many people in the industry believe that if a stone has veins, it must be marble. This is totally false. Veins can also be found in granite and limestone.

You Make Me Sick!

10. Myth: “Granite countertops harbor bacteria and emit harmful radon gas.” Truth: This is absolutely FALSE! NIOSH and the CDC have no reports of granite or any other stone used as a countertop being unsafe. If stone were unsafe or unsanitary, why would it be used in food laboratories or sold as cutting boards? There has been no known proof of any illness caused by using stone as a countertop. And as for the rumors that granite contains harmful radon gas — there is so little radon in granite that you would have to live to be 10,000 years old for it to have an ill effect on you. There is likely more radon coming from the ground and the concrete that your house is built on.