Basics of Stone Care

With basic knowledge and maintenance procedures used in a timely manner, caring for your stone product should not be a complicated chore.  Depending on its type, natural stone can be quite porous.  Without adequate protection, the surface can be marred and penetrated by everyday spills and aggressive substances such as orange juice, wine, coffee, etc.

This Old Grout & Stone’s advanced fluorochemical technology now provides penetrating sealers that protect natural stone against stains.  The sealer’s micro matrix formula actually bonds with the stone surface. Creating an invisible barrier of protection, thereby keeping spills on the surface where they can be easily and quickly removed.

Everyday general house cleaning products contain acids and alkalines that can cause damage and degrade the protective properties of stone sealers.  Also, scouring powders and abrasives will scratch the stone’s surface.  Therefore, in conjunction with the sealing application, only a ph-balanced neutral cleaner should be used to remove soil.  The proper cleaner will not only protect but it will reinforce the sealer.

The usual house cleaning procedures such as dusting, light mopping and regular vacuuming should be done in a timely fashion.  Other important protective measures:  clean-up spills immediately, use coasters on counter tops and floor mats inside and outside the home.  Floor mats and rugs absorb the grit and sand and keep it from being walked onto floors.

Natural stone is one of the most beautiful and durable of materials used in construction today.  It is unlike any other surface and requires special care and protection to insure a lifetime of beauty and pleasure.

History of Stone

MINERALS:  Minerals are the building blocks of stone and surround us in the environment.  Deposit mineral grains are found in soil, gravel, sand and rocks.  There are even mineral deposits in the air we breathe.

HARDNESS:  German crystallographer, Fredrich Mohs, was the first person to rank minerals in order of relative hardness by their ability to scratch one another.  His scale is still used today by mineralogists.

FORMATION:  Minerals form when and where temperature, pressure and chemical environment exists over a long period of time.  The length of time allows the component atoms to become ordered into a crystalline structure.  Formation time may occur over limited or broad range conditions.

ROCKS:  Rocks actually contain  a record of events that occurred during our  Earth’s long history. There are three major types of rock families;  Igneous, Sedimentary and  Metamorphic.

IGNEOUS ROCK (example: granite):  The word “igneous “ comes from the Latin  ignis, meaning “fire”. These rocks are formed by molten or partly molten rock material which is consolidated and generally called   (magma or lava) which flows out of a volcano onto land surface. This magma is derived from the Earth’s mantle or existing rocks made molten by extreme temperature and/or pressure changes. There are over 700 types, most of them formed beneath the Earth’s surface crust. 

SEDIMENTARY ROCK (example limestone & travertine):  Most sedimentary rocks are layered and many contain fossils. They hold important and fascinating history of the earth.  The preserved remains of ancient plants, animals and the composition of sediments give us clues to the original rock. The different layers  record the environmental changes of the earth over great spans of time. This type of rock forms at temperatures and pressures that preserve fossil remains. They form in three main ways—by the deposits of biogenic activity; by weathered remains of other rocks (clastic sedimentary rocks); and precipitation from solution. As particles of sediment are deposited from air, ice or water they build up and the over burden or pressure squeezes the sediment into layered solids (rock formation) and the original fluids are expelled.  Sedimentary rock covers a great amount of the Earth’s crust but represent only a thin veneer over this crust which consist mainly of igneous and metamorphic rocks.

METAMORPHIC ROCK (example: marble & slate):  These rocks are found in areas of intense distortion such as zones in the Earth’s crust where large masses of rock have been ground against one another or where heat and vapors  have permeated the nearby rocks  or where large volumes of buried rock  are under tons and tons of pressure which fosters heat build up and causes them to change or    morph .  On close examination, you can observe how flattened some of the grains in the rock have become. Therefore, Metamorphic rocks are transformation of pre-existing rocks given sufficient time to respond or change form—the process of metamorphism.

Stone Identification

GRANITE:  Granite is classified as an igneous rock that forms as lava(magma) slowly cools either at the earths surface or by intruding into pre-existing rock of the crust. The Sierra Nevada mountain range in California is a type of igneous formation known as a pluton. Time and plate interactions uplifted this igneous mass to be eventually exposed by wind, water and ice. 

Granite is composed of quartz, feldspars, micas and traces of various other minerals which fused (interlocking crystals called a crystalline structure) into the molten rock. These varied minerals give granites their beautiful variety of colors as the liquid mass is formed.

Due to its hard, dense nature and beauty, granite is one of the most popular natural stone available today. It has a broad range of elegant patterns and colors making ideal for application either outside or inside the home.

Polished granite has a shiny, mirror-like surface while honed granite has a matte or satin finish, giving it a softer less formal look.  Flamed granite is made by applying extremes of heat to create a deeply textured surface which is ideal for outside or dramatic accent in polished granite floors.  Using MOHS hardness rating (1 to 10 scale) granite measures 7 to 8.  Granite is the most maintenance-free, durable and versatile of commercial stones

MARBLE:  Marble is perhaps one of the best  known and most widely used stone type.  It has been valued for thousands of years for its rich assortment of colors ranging from white and muted beiges to browns, reds and greens.  Marble is usually polished to a mirror-like shine to bring out the rich colors.  It can be used anywhere in homes, especially foyers, bathroom floors, vanities and fireplaces. 

Some important kinds of marble are named after the location quarry:  Carrara (Italy), Pentelicus (Greece), and Proconnesus (Turkey).  Marble is metamorphic limestone composed of  a primarily even mass of interlocking calcite crystals.  The characteristic swirls and veins are usually due to various mineral impurities like iron oxide and graphite originally present as grains or layers in the limestone.

On the MOH’S hardness scale (with diamonds at 10), marble generally ranges in hardness from 4-5, therefore it is ideal for most home applications. However, high traffic areas such as counter tops can be subject to etching substances since marble is an acid sensitive stone and should be sealed with a protective penetrating sealer.

SLATE:  Slate is a fine grained metamorphic rock formed by the metamorphism of shale under lower pressures and temperatures which tends to split into sheet-like (cleavage planes) structures formed in response to differential stress..  It comes in a multitude of colors and  because it has two lines of breakability (cleavage & grain), slate can be split into thin sheets and is often used for roofing materials.  A slate roof, rather than a roof of synthetic materials is a more permanent, longer lasting choice for home builders.

QUARTZITE:  Quartzite is a very hard rock which formed by the metamorphism of quartz sandstone.  The original quartz sand grains and/or quartz silica cement and fused together by extreme heat and pressure.  Quartzite occurs in different shades of pink and red depending on the amount of iron oxide.  Pure quartzite is usually white to gray in color, but can also be purple or green.

In the formation of meta-quartzite, almost all original textures and structure have been erased.  The individual quartz grains are recrystalized along with other materials to form a interlocking mosaic of quartz crystals.

Quartzite is very strong and can withstand chemical weathering.  The resistant ridge and hilltops where it is found are often bare with little vegetation. It has a hardness measured at about 7 on MOH’s hardness scale.  Crushed quartzite is often used in railway construction.

TRAVERTINE:  Travertine (chemical sedimentary rock) is formed from calcium carbonate precipitating out of hot or cold water mineral springs that perk up through underground limestone.  The holes or voids, characteristic to travertine are the result of crystals forming in cavities after trapped gas escapes. 

Yellowstone Park produces travertine buildup from its geysers at Mammoth Hot Springs.  Extensive deposits exist at Tivoli, Italy near Rome.  The Roman Coliseum is the largest building in the world largely constructed of travertine.

Travertine is used in outside pavement or inside for countertops, floors and walls. In the fabrication process, the cavities or voids are filled with cement or resin, then honed and polished to produce a uniform look.  Travertine colors are generally light beiges and tans.

Travertine stone is acid sensitive (calcium carbonates).  Its hardness range on the MOH’S scale is from 4 to 5, making it a good choice for most applications in the home. Since high traffic areas and kitchen countertops might be subject to various etching substances, a penetrating sealer should be  applied to prevent stains.

SANDSTONE:  Sandstone (clastic sedimentary rock) is formed from cemented fragments of pre-existing rock and individual minerals . Calcite, clay and silica grains are the cement that binds  these clast togethers.  The principal that triggers sandstone formation is the sedimentation of deposits by fluids such as lakes, rivers or sea.  These environments determine the characteristics of the sandstone into two broad groups: Terrestrial (rivers & lakes) and Marine (shore face sands, deltas & sub-channels).

Ancient native American dwellings still exist today that were carved out of the side of sandstone walls over 900 years ago in Colorado.

Sandstones are most often soft and easy to work with.  They are commonly used as building and paving materials.  The feldspar and quartz sediment rocks vary in color from gray, yellow and white. 

The geographic locations for sandstone are often highly visible rock formations.  Certain colors are found in certain regions (The American West is well-known for its red sandstone).

LIMESTONE:  The various types of limestone are differentiated by the material from which they were formed.   It is a biochemical sedimentary rock, usually formed from the settling of calcite or aragonite skeletons of dead shell forming sea creatures.  It is a durable material that holds up well to exposure, therefore it has remained a very popular source for architectural buildings.  Stalagmites and stalactites form in limestone caves where mineralized solutions drip and calcium carbonates are deposited.  Arizona is home to one such cave known as Kartchner Caverns.  It boasts a column over 58 feet tall!

FLAGSTONE:  Flagstone is usually a fine-grained sandstone, bluestone, quartzite or slate.  This type of stone is commonly used on patios, driveways or paved walkway.

TERRA COTTA:  Terra cotta is low-fired clay which can be glazed or unglazed.  It is a hard baked mixture of sand and baked clay, usually with a reddish color.

CLAY BRICK:  Clay Brick is a natural mineral, mainly aluminum silicate converted or fused under the action of very high temperatures.

CONCRETE:  Concrete consists of cement, aggregate (clay and limestone) and water.  When this composite is mixed together the resulting chemical action hardens and sets into a rock-like mass.  Many ancient cultures such as the Egyptians and the Romans (who perfected it) were masters at the use of this ingenious mixture.  The formula was lost to civilization during the dark ages of Europe an was only re-discovered again in the mid 1700’s.

STUCCO:  Stucco is a mixture of water, sand and pounded marble.  It hardens into a smooth consistency which is used to cover walls and ceilings.

CEMENTITIOUS BRICK:  This block of clay is made from composed cement and baked by the sun or it is kiln cast. It is used for paving or building materials.