Best for foyers, bathrooms, floors and hearths
Marble is a metamorphic rock found in the mountainous regions of most countries of the world. Marble quarried in India, China, Italy, and Spain represents the majority of marble, in terms of volume, that is utilized worldwide. Because of its beauty and elegance, marble is a popular choice for countertops, floors, foyers, fireplace facings and hearths, walls, and windowsills.
Marble with its inherent warmth, adds a sophisticated element to the area in which it is installed. Its naturally random appearance, engineering characteristics, and ease of maintenance makes it a premium choice for floors, wall claddings, table tops, wainscot, floors, and vanity tops. Many marbles are well suited for wet area application, which extends the versatility of this material to include tub decks and showers.
The calcite crystal is the basic building block of true marbles. The calcite crystal is vulnerable to attack by mild acids, including those commonly found in kitchen and bar settings. The user selecting marble for these applications should be aware of, and accepting of the maintenance and patina that is to be anticipated with this combination. Acid rain and other weathering elements can also affect exterior marble installations, and exterior applications are generally limited to white marbles, with some exceptions.
Often mistaken for marble is serpentine, which is actually magnesium-silicate based as opposed to calcite based. As a result of the different mineralogy and whole rock chemistry of serpentine, it exhibits greater acid resistance and abrasion resistance than does a true marble. These properties make serpentine a common choice for both kitchen counter and exterior application.
Onyx is often confused with marbles, yet it is a significantly different rock type. Onyx is a sedimentary rock, formed as stalactites and stalagmites in cave interiors. This formation method results in the cryptocrystalline construction of the rock fabric, and it is the size and uniformity of these crystals that contribute to the classic translucent property of most onyx varieties. While vulnerable to chemical and abrasive attack, the decorative appeal of onyx is perhaps unsurpassed by any other material.
Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of iron oxide. Other colors, such as yellow, green, blue and orange, are due to other minerals.
Soapstone is a natural stone that varies in durability based on many factors, and it is accordingly considered one of the softest materials used in countertop constructions. It is completely stain and heat resistant. A traditional use of soapstone was the laboratory table top in chemistry labs. That application alone should serve as a great testimonial to the chemical resistance of the materials. Being of the softer varieties of dimension stone types, Soapstone is not known for particularly high abrasion or scratch resistance, yet it is often used for flooring and countertop products. Soapstone is highly heat resistant, and has been used in fireplace surrounds frequently to take advantage of this property. Maintenance is a little bit intensive as it does scratch easily, but fortunately, those scratches are easily disguised with a little bit of polishing. Nevertheless, soapstone does have a very elegant look unlike any other natural stone.
Limestone deposits exist in all continents of the earth. Despite the common and traditional reference to "travertine marble", travertine is really a type of limestone. It is actually the terrestrial (land) formed version of limestone, as opposed to the marine based formations of many other limestone varieties.
Featuring their soft earth tones, decorators integrating these stones into their design have great flexibility in selecting complimentary colors for other interior elements.
Limestone and travertine, like marble, are of a calcium carbonate base, and as such, are vulnerable to alteration by exposure to mild acids. A wide variety of stones are included in this group, and absorption varies from slight (<1%) to high (>10%). The combination of acid sensitivity and absorption limit the number of varieties that are suitable for countertop applications, and the user of limestone countertops should be well educated in its properties to accurately anticipate its behavior in service.
Limestone is a carbonate sedimentary rock that is often composed of the skeletal fragments of marine organisms such as coral, foraminifera, and mollusks. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. A closely related rock is dolomite, which contains a high percentage of the mineral dolomite, Dolomite was once referred to as magnesian limestone, a term now reserved for magnesium-deficient dolomites or magnesium-rich limestones.
Dolomite is based on the dual carbonate of calcium-magnesium carbonate, and the properties of this stone are influenced by this difference in composition. Dolomites generally have higher densities, lower absorptions, greater compressive and bending strengths, and higher abrasion resistance than the calcium carbonate based limestones. These property differences offer some application choices for dolomites where other limestone varieties are marginal or unsuitable performers.
As the popularity of natural stone installations grows each year, it also drives additional sales opportunities for care and maintenance products. The varieties of stone, the abundance of colors and textures, and the technical characteristics appeal to those seeking a premier building material for renovations, restorations or new construction.
As more and more contractors, designers, architects and homeowners are using the rich look and textures of natural stone in new ways, it has become increasingly important for sales staff, employees, business owners, contractors and homeowners to understand properties and characteristics of natural stone and the basic needs of caring for natural stone after installation.
How stone is created is important to understand, because the composition affects its density, absorption rate, hardness and appearance.
Ultimately, these characteristics determine how natural stone should be maintained to keep its beauty for life. Every region of our world is different and therefore contains unique mineral deposits due to the earth’s formation. All stones vary based on where they are quarried or excavated.
The dimensional stones used in commercial applications fall into one of these categories:
Silica is the most common mineral on Earth
Created above and below the Earth’s surface, these stones are commonly believed to have solidified from molten rock (called magma) under pressure. Underground, they are formed when magma becomes trapped in small pockets. As these pockets of magma slowly cool, the magma becomes dense igneous rocks. On the surface, when magma appears above the Earth, it is called lava. As the lava quickly cools above ground, different varieties of igneous rocks form.
GRANITE
A coarse-grained siliceous-based stone of even texture composed chiefly of quartz and feldspar minerals it usually contains small quantities of mica or hornblende. Crystallized at depth, granite masses are exposed at the Earth’s surface by crustal movement or by the erosion of overlying rocks.
OTHER IGNEOUS STONES
Quartz, Obsidian, Pumas
Created from a blend of organic materials; small pieces of our Earth that have been eroded, broken down through the action of glaciers, rivers, wind, oceans and plants. These sedimentary pieces include the skeletal remains of living organisms collected to form rock beds (carbonates). These stones have a variety of combinations.
LIMESTONE
Wholly or in large part composed of calcium carbonate, it commonly contains minerals and ancient creatures from seawater. Limestone texture varies from coarse to fine and does not show much graining or crystalline structure. It is ordinarily white but may be colored by impurities, iron oxide making it brown, yellow, or red and carbon making it blue, black, or gray. Varies in hardness, Most susceptible to staining.
TRAVERTINE
A variety of limestone and marble that contains holes formed from heat, pressure and water flowing through the stone. These holes are often filled with foreign materials such as cements or resins during the fabrication process to create a flat, polished surface. It is often beautifully colored and banded as a result of the presence of iron compounds or other (e.g., organic) impurities.
OTHER SEDIMENTARY STONES
Sandstone, Gypsum, Conglomerate
The result of the transformation of a pre-existing rock type, in a process called metamorphism, which means “change in form”. The precursor rock is subjected to extreme heat and pressure causing intense physical and/or chemical change. The precursor rock may be sedimentary rock, igneous rock, or another older metamorphic rock.
Metamorphic rocks make up a large part of the Earth’s crust and are classified by texture and by chemical and mineral assembly. They are also formed by the forces of molten rock into solid rock, particularly at the place of contact between the magma and solid rock, where the temperatures are high.
SLATE
A fine-grained stone formed when sedimentary rocks such as shale are changed by great pressure. Slate splits into wide thin layers. Slate is intermediate in hardness between rocks composed of laminated, often flaky parallel layers of mica and shale.
MARBLE
Marble was once limestone, compacted by heat and pressure that re-crystallized into marble when mineral changes occurred. This produces the colors and veining seen in the stone.
Hardness is one measure of the strength of stone. The hardness of a stone is relative to the stone’s density. Density can be a factor when considering stone types for a particular project installation.
For example, polished marble can be a beautiful addition to a residential home, but not a shopping mall floor due to the extensive care and maintenance required. The high foot traffic of a mall can eventually dull the surface of polished marble.
Stones hardness can be determined very easily. If a stone can be scratched by a known mineral from the Mohs Hardness Scale list, it is softer than that mineral. If it will scratch another known mineral, then it is harder than that mineral. In this classifi cation, the numbers assigned to objects represent the rank order (1st, 2nd, 3rd etc.) of the entities measured. The variables are called ordinal variables or rank variables. Comparisons of greater and less can be made, in addition to equality and inequality. However, operations such as conventional addition and subtraction are still meaningless.
Extremely dense stones – typically granites – are not as easily scratched, making them suitable for countertop and floor installations. Lower-density stones, such as the calcite-based stones limestone and travertine, are frequently used in lower traffic areas for aesthetics and beauty.There is an easy, practical way to test the hardness of a stone through a scratch test. You may apply this test on the top or back sides of a piece of stone. (Warning: do not conduct this test on the surface of an installed stone – it may ruin the stone.) Using a box knife steel blade, simply score it across the stone’s surface. Do not apply hard pressure. A stone categorized as granite (quartz/feldspar) will not typically scratch. Because granite has a higher tolerance to scratching, it is widely used on countertops. Marble, travertine, limestone or slate will usually scratch fairly easily with a sharp knife.
Rough stone blocks are extracted from quarries around the world and then shipped to a fabrication plant. The stone blocks are put through a series of processing steps, depending upon the end product desired. These steps include cutting the block into thin slabs, polishing the slabs, and cutting thin slabs into floor tiles or veneer for building exteriors (curtain). Equipment used in fabricating stone includes diamond wire saws, large blade saws with diamond inserts, and saws durable enough to cut thick slabs for monuments. Computer-controlled machines are capable of easily cutting intricate shapes to satisfy the needs of architects and designers.
The fabrication of the stone will affect its porosity and its appearance. There are many types of textures applied or fabricated to dimensional stone surfaces. This list shows some of the more popularly used fabrication methods applied to stone.
POLISHED
A glossy, highly reflective surface
TUMBLED
A slightly rough texture that is achieved by tumbling small pieces of marble, limestone or granite to achieve an old-world/worn appearance
HONED
A flat matte to low sheen gloss
SAND BLASTED
Pressurized flow of sand and water that results in a matte finish
FLAMED
Rough surface developed through intense heat
BUSH-HAMMERED
Pounding action of hammer develops textured surface. Reduces stone’s color tones
Acid-based cleaners will slowly damage the appearance of calcium-based stone. The acid creates bigger pores for increased staining potential. It also chemically reacts with the stone causing damage and etching. Some household cleaners can be labeled “tile cleaner” or “all-purpose cleaner”, but can still be very acidic and will damage many types of stone and grout.
Because carbonates (marble, travertine or limestone) react to acid (acidic cleaners) to create carbon dioxide, the effects to the stone are permanent. The destruction of carbonates shows on the surface of stone as etching. Although the particles of stone cannot be recovered, they can be polished or refinished to match the finish of the stone. CaCO3 + acid = CO2 + H2O + Ca2+ Heavy-duty cleaners and strippers containing alkali are ideal for special circumstances requiring deep cleaning – but should only be used on an occasional basis to remove or strip acrylic finishes, waxes, dirt, oil, and penetrating sealers.
Aqua Mix® have a range of stone restoration products that are designed to repair and restore marble, travertine & limestone surfaces. Aqua Mix® Reviver® is a user-friendly, highly-effective, ready-mixed paste for polish restoration and maintenance of worn calcium based polished stone. Ideal for large areas. Aqua Mix® Knockdown® is a non-acidic honing powder that removes light surface scratches, moderate acid etching and wear patterns to produce a flat, even and honed finish. It is excellent for safely honing polished marble, limestone or travertine to a smooth honed surface when a honed, unpolished finish is desired.
The pH (p=potential of, H=Hydrogen) balance scale measures the acidity or alkalinity of a solution on a scale from 1 to 14. Neutral solutions are rated as a 7. From 7, the number increases with alkalinity and decrease with acidity. Each number from 7 (neutral) is 10x stronger than the previous number.
All Aqua Mix cleaners are non-acidic, they safely clean stone surfaces with formulas designed for both routine or heavy-duty cleaning.
The pores and capillaries of stone affect the amount of water that can evaporate through stone – also known as moisture vapor. Moisture vapor is carried from the substrate through the stone to keep the substrate dry– through a process referred to as moisture vapor transmission (MVT). MVT allows the stone to “breathe” naturally, reducing the possibility of mold growth, damage to the substrate, or stone discoloration.
Note: Finishing sealers create a topical finish, covering the stone’s surface, to help repel water and oil. However, based on the job application or improperly-prepared installations, some finishing sealers can trap moisture or inhibit MVT. Most penetrating sealers do not inhibit MVT. Be aware of the type of application, and read all manufacturers’ directions, when selecting a sealer.
Premium sealers contain higher quality active ingredients than their more economical counterparts, delivering complete coverage of the gaps in the stone to provide better stain resistance, regardless of porosity and density. Dense stones need smaller sealer molecules to fit into the smaller pores in the surface. Penetrating, water-based sealers offer excellent protection for stone with water as the carrier. Solvent-based sealers protect and penetrate with solvent-based carriers.The choice between a water-based and solvent-based sealer is a matter of intended application. As long as both are premium sealers, they will offer maximum levels of protection.
Active ingredients, or solids, bond with stone and fill in the gaps, or pores, to penetrate the surface. What doesn’t penetrate the surface gets wiped away.
Illustration shows a Penetrating Sealer as if under powerful magnification. Note the various sealing molecules that penetrate and bond to the stone’s surface.