Prologue

Natural stone is beautiful, representative, and thanks to modern techniques of quarrying, manufacturing, and processing, affordable for almost anyone. Each slab is a piece of nature and, therefore, unique.

Natural stone remains, ‘naturally,’ unchanged over centuries; it is not subject to the constant fluctuations of market currents, to what is ‘hip’ and ‘fashionable,’ as is the case with artificial/synthetic materials. Furthermore, natural stone provides the designer with many a possibility of usage and application. Flooring and paneling can be treated with a number of surface applications: depending on the surface treatment, the stone appears lighter or darker, its colors can be more or less intense, it can feel smoother or rougher. Natural stone can be manufactured in massively diverse ways. As such, flooring and paneling, processed, to offer just one example, with ceramic tiles, can be complemented with as many other items as massive shower trays, washbasin, shells and panels, basin and pool bordures, monolithic bathtubs, and even sculptures.

There is a plethora of different stones with a wide variety of colors and textures, each one with its own properties and characteristics. This individual variety comes with its own structural-physical properties.

Now, this rich variety can be both a blessing and a curse. It can be the reason for wrong choices and improper treatment regarding cleaning, protection, and care. These mistakes in treatment cause problems which can often, unfortunately and unjustifiably, bring natural stones into discredit. Even misnomers, such as referring to all hard stones as “granite,” have led to an unjust discrediting. Not all hard stones are “granites,” and very often what is referred to as “granite” is not a genuine granite in the stricter sense.

This guide provides the consumer with an “easy-to-read” manual in the form of questions and answers and helps him or her to master the daily challenges of preserving the original quality of natural stones in order to enjoy for the longest possible time this precious and valuable material.

Section-1. TYPES OF NATURAL STONE

Q1. What is the difference between granite, marble, limestone, sandstone, slate ?

The difference between miscellaneous types of natural stone starts right with the origin of its creation:

Granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume. Marble is a non-foliated metamorphic rock composed of recrystallized carbonate minerals, mostly common calcite or dolomite. Marble, in other words, is a metamorphosed limestone. Limestone is a non-foliated metamorphic rock (sedimentary rock) composed, mainly of skeletal fragments of marine organisms such as coral, forams and mollusks. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO₃). Sandstone is a sedimentary rock composed mostly of sand sized minerals or rock grains. Slate is a finely grained, foliated homogeneous metamorphic rock, derived from the original shale-type sedimentary rock, composed of clay or volcanic ash, by means of low grade regional metamorphism.

Each of these different varieties has their own properties and appearance, and requires therefore an individual approach and differing applications.

Q2. What is hard and soft stone?

Generally, stones are categorized into hard and soft stones.

“Hard stones” include granite, gabbro, syenite, and diabase. The materials subsumed under this category are wear-resistant and in most cases suitable for all forms of installation. Commercially, these stones are mistakenly referred to as “granite.” Equally classified as “hard stones” are porous vulcanite and slate stones. These, too, are suitable for any kind of installation.

“Soft stones” range from so-called sedimentary rock such as limestone and argillaceous shale to metamorphic rocks such as marble. In most cases suitable for flooring, these stones are mostly used for paneling and less demanded areas. Commercially, these stones are commonly referred to as “marble” or “limestone.” Sandstones, too, offer a variety of possible applications if used as soft stones, preferably as flooring material.

Q3. What is the stability of the natural stones against acidic chemicals?

Is the natural stone acid-sensitive (limestone, marble, many sand stones, argillaceous stone), then those chemicals are not to be used:

Generally, soft stone (such as limestone, marble, many sand stones, argillaceous stone) are acid-sensitive and are therefore not to be treated with acidic chemicals. Hard stones (such as granite), on the other hand, are acid-proof. However, the general classification of “granite” includes some gabbro and basalts which are not acid-proof, such as, the Indian Star Galaxy or the South-African Nero Absoluto and Impala, as well as different kinds of diorites such as the Brazilian stone Tijuca. These “relatives” of granite consist of a wholly different chemical composition and can therefore not be classified as granites. Additionally, what is commonly referred to as “black granites” include natural stones which are not granites at all and which, therefore, are also not acid-proof.

Q4. How to choose the right natural stone for a project?

Besides the appearance, colors and design of the natural stone the most important criteria for choosing the appropriate climate for indoor and outdoor applications are: frost resistance, abrasiveness, water absorption, acid resistance, suitability for flooring and cladding, polishing possibility.

Section-2. PRE-INSTALLATION CARE OF NATURAL STONE

(In the factory or outside factory stage)

Q5. Why is it necessary to pre-protect the stones before application?

The main concern before application is begun is how to protect the stone against attacks. Protection concerns all six sides (surfaces) of the stone.

Q6. How to pre-protect the Natural Stone for indoor application?

Flooring and Walls (Façade dry-cladding): The best way to prevent blooming and stains caused by moisture and to avoid or reduce rust stains is to impregnate all six sides (surfaces) with a suitable solvent- or water-based Stone Protector.

Walls (Façade wet-cladding): In case of wet-cladding it is recommended to seal the back-side of the natural stone with a thin coating layer of a 2-component resin system with quartz sand dispersed on it. The quartz sand layer acts as an adhesion primer to the laying cement mortar. Treat the remaining 5 sides with a suitable solvent- or water-based Stone Protector.

Q7. How to pre-protect the Natural Stone for out-door application?

Flooring and Walls (Façade wet-cladding): In both cases it is recommended to seal the back-side of the natural stone with a thin coating layer of a 2-component resin system with quartz sand dispersed on it. The quartz sand layer acts as an adhesion primer to the laying cement mortar. Treat the remaining 5 sides with a suitable solvent- or water-based Stone Protector.

Q8. How to pre-protect the Natural Stones (marble as well as granite) by laying a floor or to install by wet-cladding, if the back-side is already treated (protected) with net and resin, which could not adhere, using a cement mortar?

In both cases it is recommended to treat the back-side of the natural stone with a thin coating layer of a 2-component resin system with quartz sand dispersed on it. The quartz sand layer acts as an adhesion primer to the laying cement mortar. The other 5 sides we treat with a suitable solvent- or water-based Stone Protector.

Walls (Façade dry-cladding): The best way to prevent stains caused by moisture is to impregnate all the six sides with a suitable solvent- or water-based Stone Protector.

Section-3. POST INSTALLATION STONE CARE

After the end of installation two important procedures follow: the initial post-installation cleaning and the basic protection.

3.1. Initial Post-Installation Cleaning

Q9. With what forms of staining and dirt are we dealing with?

1. Cleaning blown-up coarse dirt (e.g. sand) and fine dirt (e.g. coarse dust).
2. Cleaning adhering dirt, either water-soluble (e.g. soil or fine dust) or not water-soluble (e.g. residues of mortar, cement, or joint fillings, putty, adhesive labels, marker-lines)
3. Cleaning special stains (e.g. residues of epoxy resin or stains caused by packaging material that had been placed onto the surface).

Q10. How can coarse dirt be removed?

Coarse dirt can only be removed mechanically by using an upright vacuum cleaner or vacuum sweeper. Do not use a broom, since that would blow up quartziferrous dusts which are highly damaging to one’s health. Avoiding any production or proliferation of dust is paramount.

Q11. How can I remove the adhering dirt (water-solvent)?

Water-solvent dirt is removed by damp- or wet-wiping. With vacuum scrubbing a mechanical support is being provided (scrubbing) that helps unstick and detach of adhering dirt while suctioning the dirty water. Same goes for wet scrubbing with brush or pad and subsequent wet suctioning.

Q12. How can I remove the adhering dirt and stains (not water-soluble)?

Dirt and stains that cannot be removed with water are differentiated based on their solubility:
- Dirt and stains that can be removed with acidic cleaning products, e.g. cement residue, mortar residue
- Dirt and stains that can be removed with alkaline cleaning products, e.g. waxes, fats, general soiling’s.
- Dirt and stains that can be removed with solvent cleaning products, e.g. oils, adhesive tapes.

Q13. How can cement residues be removed without damaging the stone surface?

Considerable maltreatments can happen with the cement residue removal. Cement residue are rests of cement join fillings sticking to the floor surface. These can only be removed by using acidic solvents. Cement residue removers are, consequently, acidic products, which dissolve residues of cement and lime. The composition of the products (kind and concentration of the acid) can vary considerably. Every kind of acid has its pitfalls and not all of them are universally applicable to all natural work stones. Depending on surface treatment and intensity of pollution, mechanical assistance should be added to every application of cement residue remover.

If the stone is not acid-resistant, a mechanical removal with an alkaline solvent can be attempted; however, the cleaning product will not immediately and entirely remove dirt from the surface.

In the acid-sensitive natural stone with a rough surface, removing cement residues presents a different situation. Often one is faced with the question of whether to grind over or rework the natural stone to the entire floor material. In this case, it is possible to use a highly-diluted cement residue remover after having pre-wetted the surface in order to acidify the surface, if the resulting roughening of the stone remains unperceivable on its rough surface and the damage remains within acceptable terms.

Q14. Why do I have to pre-wet the acid-sensitive natural stone before applying acidic chemicals?

The easiest way to protect both the natural stone and the joints from acid is to pre-wet the floor. The rule is simple: if water has got in, then acid cannot get in. The cement residues then lie on the surface and can be dissolved by the acidic influence. Most cement residue removers dissolve the cement, but do not clean the its surface. For the sake of neutralization, the flooring must be cleaned with an alkaline basic cleaner. It is advisable to always test the product on an inconspicuous area, since it is never completely clear what the exact reaction is going to be between stone and product.

Q15. What happens with the joints during the cleaning process?

The joints are very acid-sensitive, even those made of synthetic material. As a general rule, there should be a ten-days waiting period between the jointing and the cement residue removal. Additionally, pay attention to the guidelines of the grout manufacturer.

3.2. Post-Installation Protection (Basic Protection)

Q17. Is a final protection necessary?

Yes. The pre-protected surface of natural stone after the intensive cleaning with more-or-less strong chemicals and in addition to the mechanical strain during the cleaning is not enough for a long-lasting protection. In case the natural stone after laying will be reground and re-polished (mainly for soft stones),a basic protection is compulsory.

Q18. How many kinds of protection do we have at our disposal?

For the care and protection of natural work stones two basic groups of processes and products are available:
- Impregnation (not layer-forming products) and
- Sealing (layer-forming products)

Impregnations are classified as water-repellent (hydrophobic) and water- and oil-repellent (hydro- and oleophobic). The applied impregnation product penetrates into the surface pores of the stone and is taken up by the poricidal walls. A capillary transmission of fluids into the stone is made impossible. Impregnation products do not entirely close up the pores of the natural stone, however, transmission of water is only possible in the form of vapor, no longer in liquid form (water vapor diffusion). Depending on the product, the rate of water vapor diffusion may equally decline.

Q19. What is the difference between sealing and impregnation?

Unfortunately, in the English language, we use for both kinds of protection, the word “sealer”, “sealing”. The word “sealing” in case of impregnation is misleading. It implies that the stone is so entirely covered that it is unable to breathe, which is not the basic property of the impregnation.

Sealing can be achieved; however, it depends on the kind of stone. For example, we could do sealing on “sheet stone” like slate, or where the back-side of natural stone is open to ventilation (e.g. ventilated façade).

Impregnations are not layer-forming, but penetrate into the stone structure and cause a visible reaction on the poricidal surface. They emulate the natural vapor diffusion rate of the stone. Therefore, they do not provide a complete protection against stains, they solely prevent stain-producing substances from entering too easily into the stone. Impregnations do not provide protection against acids, such as those found in fruit juices.

Sealings, on the other hand, are layer-forming products. They should not be applied to backstage moistened coverings since they prevent a diffusion of humidity and can therefore cause discolorations and whitening underneath the covering. Sealings should not be used on or around kitchen countertops, since they are not particularly heat-resistant or scratch-proof. To avoid unnecessary trouble or reclamations, the costumer or client should be thoroughly briefed beforehand.

Q20. Who should perform the impregnation?

In general, a stone expert, e.g. a stonemason, who is familiar with the impregnation of flooring and other surfaces made of natural stone. The person should, however, prove conversant with the application of adequate products as well.

Q21. Can impregnation protect the stone from acidic influences?

Impregnations provide primary protection, i.e. the absorption of stain-forming substances is being delayed and reduced by impregnation. Impregnation does not protect against acidic influences. It is important to remember that drinks such as fruit juices, sparkling water, fizzy drinks etc. are considerably acidic and can attack acid-sensitive stones. Stains caused by acidic influence are therefore immediately to be removed.

Q22. How many different types of impregnation products are there?

Depending on the respective solvent and effects, impregnations are categorized into:
- water-repellent (hydrophobic), water-based, without color-enhancing
- water-repellent (hydrophobic), solvent-based, with and without color-enhancing
- water- and oil-repellent (hydrophobic and oleophobic), water-based without color-enhancing
- water- and oil-repellent (hydrophobic and oleophobic), solvent-based with and without color-enhancing

It is important to note that even with impregnation products which are not color-enhancing, a deepening of color, albeit a slight one, can occur the color depending on the stone. Therefore, a test-application on a sample area should be conducted before the actual procedure. If need be, obtain previously an official approval from the client. In certain cases, a more or less intensive deepening of color might be in the client’s interest.

Solvent-based impregnations give the impression of a more intense color. Thanks to their superior penetrating properties, these products achieve a better effect on stones with diminished absorption.

Q23. What does one have to take care of before beginning with the impregnation?

A dry and cleaned stone surface is especially important for a successful impregnation. Before any impregnation, the surface must be dried and cleaned. All stains must have been removed and the surface should be absorbing. A thorough cleaning is the essential pre-condition for a later successful protective treatment. Stains that have not been properly removed before treatment are a lot more noticeable and much harder to remove post-impregnation.

Q24. How can one decide on a water-based or solvent-based product?

Dry stones have higher absorption capabilities and are therefore better suited for solvent-based impregnation, which provide a superior protection compared to water-based impregnations. However, solvent-based impregnation cannot penetrate a wet stone and then sink into its capillary structure. Should the stone be considerably moist or not properly dried, the following problems can occur during a solvent-based impregnation:
1. Film formation on the stone surface
2. Proper drying is hindered due to temporary clogging of the capillary (possible spotting due to internally harboured salts)
3. Adverse reaction of the agent with the prevailing moisture (permanent discoloration)
4. Insufficient protection effect can cause marginal damages.

Water-based impregnation is suitable for natural stones which are difficult to dry well. Water-based impregnation has decreased penetration properties on less-absorbing stones. It therefore achieves a less than ideal protective effect, but also does have less “damage potential.” If applied, the following problems can occur:
1. Insufficient protective effect
2. Film formation on the stone surface

Q25. What causes problems during and after impregnation?

When it comes to impregnation, the following conditions can cause problems:
1. Too much remaining moisture after laying and cleaning, respectively.
2. Overapplication: surplus on the stone surface (film formation).
3. Underapplication: too sparingly applied product leads to insufficient protection.
4. Stone warming (sunlight exposure, underfloor heating) causes film formation due to the solvent evaporating too rapidly.
5. Insufficient pre-cleaning (rests of cement residue, other forms of pollution and residue of previously applied care products).
6. Exposure to humidity immediately following impregnation (especially in outdoor areas, e.g. rain).

Q26. What is the behavior of “dark stones” to impregnation?

Several dark stones can alter their color after an impregnation treatment. In many cases, this is a desired effect. There are many natural stones, however, which react differently to impregnation solutions and end up covered in stains and spots. This often happens in rough materials such as quartzites and gneiss. Other stones, such as the Norwegian Otta Phyllit, can lose their so-called 3D-effect, a three-dimensionally looking shimmering on the surface, after an impregnating treatment. The impregnation of such sensitive kinds of natural stone specially require an impregnation with Nano-effect. These products are applied onto the clean and dry surface. After an application time of 5-10 min. the residues are being removed. The full impregnating effect sets in just after 2 hours. The product does not cause any color deepening.

Q27. How can I determine the dryness of the stone surface?

There is a simple test to determine whether the stone surface is sufficiently dry. Lay a foil or newspaper over the surface. A “sweaty” foil or a “wrinkly” newspaper point towards a prevalent humidity. This test might be imprecise, but can be easily executed.

It is important to stick to the necessary waiting time between cleaning and application. Often, a floor surfacing seems to be completely dry within an hour after cleaning. This appearance may be deceiving. Far from being dry, the stone may be completely soaked inside its capillaries. The duration of the drying time depends, among other things, on the absorbing capacities of the stone and climatic conditions such as temperature and humidity as well as existing ventilation.

Q28. Which tools are used to apply stone impregnation?

To impregnate a stone, the product should be applied fully and evenly with a paintbrush, seal brush, flat dust mop, and short paint roller in a cross stitch pattern. Impregnations can be sprayed too, e.g. on vertical areas. Liquid impregnations are best sprayed onto the surface, since this technique facilitates a more even application than using a roller. During application, it is important to avoid leaving behind puddles. Surplus material must be removed with cloth or paper before drying up.

Q29. Is possible to repeat the impregnation?

Re-impregnations are unproblematic with liquid products, but can cause problems with solvent-based products. It is therefore advisable to apply sufficient impregnations and to facilitate an immediate and complete absorption, since a surplus of impregnation will cause a film formation on the surface which will then have to be removed. A film on a stone surface impregnated with solvent-based products will cause uneven abrasion under mechanical exposure (e.g. footprints). Such films can easily be removed up to one week after impregnation with a basic cleaner or an impregnation remover. Nowadays, many natural stones with polished surfaces have been pre-treated as early as in the factory (resination) stage. As a result, the stone’s absorption properties are highly diminished. Surfaces of these stones can change considerably when treated with solvent-based products.

Q30. What is the Life-time of impregnations?

Regarding liquid and solvent-containing impregnations, the life-time of the treatment depends strongly on cleaning and care of the impregnated areas. If cleaned with alkaline substances, water- and oil-repellant impregnations are much durable than impregnations that are only water-repellant. Kitchen countertops should be re-impregnated once a year, surface coatings in bathrooms or swimming areas once every three years (showers and washstands once a year). For coatings in regularly utilized areas which are carefully maintained re-impregnation should be considered every 5 to 10 years.

3.3. Maintenance of Natural Stone

Q31. Which are the well-established cleaning methods?

Sweeping:
The old-fashioned broom is still a valuable part of everyday maintenance of any floor surface – natural stone included. It is very important to remove soils from flooring surfaces. Soils are abrasive. The more often soils are removed, the longer the floor will retain the original appearance. Use a broom with a bristle that matches your surface. A soft broom or brush is recommended for smooth surfaces like marble, sandstone and limestone. A medium to soft bristle is ideal for textured surface.

Vacuum:
A good vacuum cleaner works better and more efficiently on textured surface than a broom. Use a vacuum on any horizontal surface when large areas are involved, since it is, in most cases, faster than sweeping.

Damp Moping:
A damp mop is capable of picking up microscopic abrasive soils and potential staining agents. Damp mopping is recommended for most smooth surfaces on a regular basis. Best done after sweeping or vacuuming.

Cleaning:
It is essential to clean a floor regularly. The working conditions will dictate its frequency. The most widespread problems encountered with stone floors are related to the floor simply not being regularly cleaned.

Rinsing:
Rinsing is one of the most critical steps in regular floor maintenance. Dirty mop water residue is common and a cause for much complaint. A two bucket rinse method is highly effective in keeping floors from graying out due to soil residues.

Abrasive (mechanical cleaning):
Abrasives are sometimes useful as a cleaning agent but should be limited to non – polished surfaces. Abrasives may be combined with detergents or soaps for scouring a surface and removing thin layers from the surface. There are many different types of materials used as abrasives – soft abrasives may be composed of nutshells or feldspars, hard abrasives can be silica quartz, carbide or even diamond.

Q32. What can ruin or cause damage to a stone?

Acid:
Spills from drinking liquids or food containing acid will etch (dull mark) marble and limestone surface. Also the wrong declaration of some group of natural stones can cause irreparable damages. The so called “black granites” which are partially basalt such as Tiger Black or Chinese G684 or Gabbro as Star Galaxy, Nero Absolute, Impala or in the case of Belgian granite, which is limestone, all of them are sensitive against acid. In such cases, lemon juice, orange juice, carbonated beverages, cranberry juice, apple juice, wine, tomato, etc. may cause a dull mark that may be of a coin size or spread over the surface.

Alkaline:
In addition to chemicals containing acid, chemicals that contain high alkaline or bleach can damage floors to lose its shine and elegance.

Moisture:
Local water may contain chlorine, salts, magnesium, potassium and other minerals. When water is used continuously to clean the marble and limestone floor it may ruin certain type of marble or limestone by causing pitting, spalling and yellowing. This is why it is important to protect the floor with a sealer (impregnator).

Scratches:
Sand and grit carried from outside by shoes can easily scratch and abrade the marble surface like a sandpaper. Unprotected furniture legs may leave scratches too. Dragging heavy objects or sharp items on the floor can cause very deep scratches or gouges that may be permanent.

Stains:
Even a hard, natural stone such as granite is still porous and can easily be discolored by spills from food, sitting pots, metal furniture legs, oil, ink, water damage, etc.

Improper Maintenance procedure:
Continuous use of water as the sole cleaning agent (without chemicals), or using dirty mops, or not changing the cleaning solution frequently enough, can cause soft and hard stone to look dingy, streaky and unattractive.

Improper Maintenance program:
Not having a steady use of dust mop and damp mop cause a decrease of the gloss. In addition, a yearly maintenance may be required to revive the gloss especially when the floor is exposed to medium or heavy traffic.

Q33. What are the recommendations for a successful initial (basic) cleaning?

◼   For Floor / Stairs (indoor)

1. Soft stone such as marble, limestone (not stable against acidic cleaner).
For contaminates such as basic dirt, dirt layers, thin layers of wax, superficial oil and grease stains, soot, rubber and tar stains, even efflorescence and cement rest -
Clean with a light alkali cleaner (pH=10). Don’t start with the concentrate form. Depending on the dirtiness, start with a water dilution 1:5 to 1:25.

2. Hard stone such as granite, gneiss (stable against acidic cleaners).
Clean with alkali cleaner as well as with acidic cleaner (pH=1). Because many of the hard stones such as the so-called “black granite” (Tiger Black, G684) are not stable, it is necessary to conduct a pre-treatment test with the acidic cleaner on an inconspicuous area. Do not use immediately in concentrated form and pre-wet the surface. Acidic cleaner based on hydrochloric acid react with many hard stones to cause rust. Other hard stones as Labrador lose their gloss immediately. Acidic cleaner based on acetic acid attacks the fittings.

◼   For Façade, Wall terrace (outdoor)

1. Soft stone such as marble, limestone (not stable against acidic cleaner).
Clean with a light alkali cleaner (pH=10), algae & mildew remover, which is a slightly alkali cleaner (pH=11) based on active chlorine compounds. Use undiluted. Do not allow contact with plants, metal, wood and cloths.

2. Hard stone such as granite, gneiss (stable against acidic cleaners).
It is possible to clean with alkali cleaner as well as with acidic cleaner or/and algae & mildew remover.

◼   Kitchen-countertop, Wash basin, Sanitary items

1. Soft stone such as marble, limestone (not stable against acidic cleaner).
Clean with an alkali cleaner (pH=10)

2. Hard stone as granite, gneiss (stable against acidic cleaners.
Clean with a strong alkali cleaner (pH=12)

Q34. What are the recommendations for a successful daily cleaning?

It is usually not necessary to clean daily unless it is a high traffic area like hotel lobby, etc. For all floors the daily cleaning should be carried out by a cleaning product with pH = 7 neutral and water-based.

Clean with a neutral cleaner (pH=7) or stone soap. Surfaces are to be slightly moisted with a wiper to remove the dirt. Dilute the concentrated cleaner in water 1:50 to 1:100 and clean the surface with a slightly moistened cloth. Let the surface dry for 10 minutes. The products can also be used in a brush cleaning machine with a sucking device.

It is important to prevent the product from creating layers or stripes on the floor to support the protective effect of the impregnation. The water solution of the cleaning product should be applied with a mop. Dirty solutions should be mopped up regularly. Remove loose debris by sweeping or vacuuming before applying the cleaning solution.

Q35. Which are the recommendations for a successful periodical cleaning?

◼   Periodical initial (basic) cleaning

Due to heavy traffic or other circumstances it can be necessary to carry out periodically an initial cleaning with a slightly alkaline cleaner. The application period depends on the grade of pollution; it can be carried out every 3-12 month.
The product has to be diluted with water approximately 1:20 up to 1:50 depending, on the degree of pollution.
The product must not affect the impregnation of the stone.
The cleaning solution should be applied with a mop. Dirty solution should be mopped up regularly.

◼   Spot and stain cleaning

Although impregnation is used, it can be at times necessary to remove spots of heavy pollution and stains. If required, preferred products are:
Rust remover for granite or for marble, Oil- and Grease Remover, Algae- and Mildew Remover etc. Also, bleaches are typically oxidizing agents (they generate oxygen) and are useful in stain removal. Enzyme types are available which are non – hazardous.

Q36. How to protect natural stones used for highly strained surfaces as such as kitchentop, table top, bar counter etc.?

Protection:
The surface of the natural stone has to be clean, stain free, dry and with enough absorption properties. Nowadays most of the natural stones are already treated in the factory. As a result, the stones show altered absorption properties. Therefore it is recommended to use an oil- and water-repellent, solvent-based impregnation. In any case is recommended to prepare a sample area in order to examine the efficiency of the impregnation.

Due to the permanent contact of impregnation with foods, is essential that the protection is approved as being of food-safe quality.

Q37. How to clean and care natural stones used for highly strained surfaces as kitchen tops, table tops, bar counter etc.?

Cleaning and care:
If cleaned immediately, many food stains can be taken care of with a simple damp cloth. Once dried up or involving fat, stains and soiling can no longer be cleaned so easily. For such residues, mild cleaning products with oil- and fat-solvent qualities should be used. Products that are extremely alkaline or highly degreasing can, over the long-term, damage the stone’s impregnation. Many manufacturers offer spray cleaners that are easily applied. They have a cleaning and protecting component and therefore provide a removal of stains and protection of the stone in one single working step. If used regularly, the spray cleaners can prolong the interval time between subsequent impregnations.

At the first sight of dark stains caused by oil- and fat-containing food, an immediate reaction is essential. Among the most effective solutions are oil removal pastes. These cleaning products guarantee a long application time, an essential factor if pollutions need to be dissolved that are deep-seated within capillary structures of the stone. After the removal of stains the protective impregnation needs to be renewed.

Section-4. REMOVING STAINS

Q38. How to remove stains from the surface of natural stone?

1. Soft stone such as marble, limestone (not stable against acidic cleaner).

If there are contaminates such as; basic dirt, dirt layers, thin layers of wax, superficial oil and grease stains, soot, rubber and tar stains, or even efflorescence and cement residue -
Remove with a light alkaline cleaner (pH=10).

What to do if there are superficial rust stains produced by ferrous substances or objects, such as fertilizers, tools, iron pasts etc. -
Remove with a slightly alkali rust remover (pH=9)

2.Hard stone such as granite, gneiss (stable against acidic cleaners).

If there is rust and inorganic discoloration: to remove inorganic discolorations, such as rust stains, use Rust remover, a product based on phosphoric acid. It is important to make a test patch in an inconspicuous area to ensure that the surface is acid resistant.

If there are lime residues, rust marks and heavy soap residues: They can be removed with an organic acid based disinfectant cleaner with (pH=1)

Mortar, lime residue, efflorescence, cements films and other stubborn deposits on tiles or slabs:
They can be removed with an acid-based concrete film remover, which is free of hydrochloric acid.

Section-4. TIPS TO AVOID MISTAKES

Q39. What are the main mistakes in maintenance?

1.  Cleaning only with water
2.  Not replacing the cleaning solution
3.  Cleaning mop head is not kept clean
4.  Floor is not vacuumed or dusted enough
5.  Not using a door mat
6.  Using the wrong cleaning chemical
7.  Not having a planned program for maintenance

Q40. Are they some tips to avoid mistakes during maintenance?

Here are some useful tips-

Use walk – off mats
To reduce the possibility of unsightly scratches and/or dulling of the marble or limestone floor, install walk off mats inside and outside all entry doorways. Good quality walk-off mats will remove sand and grit from the bottom of a person’s shoe that could otherwise badly scratch and dull the marble floor.

Dust Mop & Sweep Regularly
Walk-off mats will reduce the amount of abrasive soils that can enter from shoes, however, they cannot completely eliminate all materials that can scratch or dull a stone surface. Many abrasive soils are generated inside the house like very small pieces of broken glass or porcelain, metal chips or flakes, or sand and dirt brought in/on clothing or other materials. Dust mopping and sweeping will help remove these abrasive contaminants. Use a clean, untreated and dry dust mop or fine bristle broom and dust pan to remove all dust, dirt and loose debris daily or as needed. This is the most important thing you can do to keep the stone surface looking new.

Utilizing a neutral non – residual water based stone cleaner or a slightly alkali cleaner, damp mop regularly. Spot cleaning can be accomplished by simply applying a small amount of this neutral cleaner to a soiled spot, lightly rubbing to dissolve the spot and remove with a clean damp sponge.

Don’t clean only with water
This can be very detrimental to your soft stone. Water contains chlorine, salts and other minerals that will diminish the shine if used on a regular basis. In addition, water doesn’t have the ability to cut through dirt and mainly dust will be removed. Utilize neutral, non-residual water based stone cleaner, damp mop regularly. Spot cleaning can be accomplished by simply applying a small amount of this neutral cleaner to a soiled spot, lightly rubbing to dissolve the spot and removing with a clean damp sponge.

Replace the cleaning solution frequently
Otherwise, it will leave streaks all over the stone surface and the grout joints (especially if they are light colour) will get dirty very rapidly. Whenever you notice that the cleaning solution becomes cloudy and dirty, immediately replace it with a fresh new solution.

Keep the cleaning mop head always clean
By using mop or cloths that are soiled and dirty, you are actually tracking the dirt back into the floor and grout joints. Dirty mops can create streaks and an unattractive look. Keep the cloth or mop head clean all the time. Wash them thoroughly after you have finished the cleaning with neutral soap and warm water.

Use the right cleaning chemicals
In case you use the wrong cleaning chemical you can ruin your stone floor very easily. Especially soft stones made from calcium carbonate are very sensitive to any acid or high alkaline chemicals. Do not use any tile cleaners, vinegar, ammonia, alcohol etc. Use only neutral cleaners that have pH 7.00 or slightly higher and were made specially for cleaning stone. In this way you prolong the stone life.

Make a planned program for maintenance
Designate the cleaning days and polishing dates and the days that you want to re-apply the protection depending on the abuse and foot traffic. Doing that will keep the floor well maintained.

Section-5. GENERAL INFORMATION

Videos and Presentations will be made available soon.

I-1. Videos

- How to make Anti-slippage floorings
- How to apply an oil- and water repellent protection on a kitchen top
- How to apply a color enhancing protection
- How to renew the gloss of a stone floor
- How to remove acidic stains and lime scale
- How to remove organic discolorations
- How to repair small holes and scratches (fine cracks) without having to regrind and re-polish the whole surface

I-2. Power-Point

- How to repair and renew an old floor

Introduction: IMPORTANCE OF KNOWING THE STONE MATERIALS

Natural stone is one of the most ancient building materials that has accompanied us since our origins. However, strangely, it remains unknown in so many ways to most of us.

To know the materials and understand their technical characteristics has become indispensable for the industry since offering this information to all the interested agents will make its use easier.

The aim of this Guide is to give technical information on natural stone so as to increase the knowledge of it, the specifications and use.

Technical Characteristics Of Stone

When electing a material we need to know its capabilities that will adapt to the project.

One should to take into account that all the stones have possible uses, but not all the stones can be used for all the applications. To give an example: knowing what is the degree of absorption of water of a stone will help us to decide if it is valid or not for use as cladding material in a swimming pool.

How can one know what are the characteristics on which to focus for a stone for a particular use? We will now try to summarise them below.

From Where Do The Norms Come Which Define The Requisites Of A Stone For Construction?

The requirements for a stone will depend on the country where the stone is found or the country of its destination.

We can find requisites related to the material itself (granite, marble, limestone, etc.) with the construction producto (tiles for pavements, slabs for facades, etc.) or the construction system used.

How Does One Know What Tests Need To Be Done To The Materials?

It is important to know that, from one country to another, the requisites needed as also the testing methods may vary by which one arrives at a result.

For example, the ASTM norms indicate some minimum values for the type of stone being examined, however, in the majority of the European countries there is no limit for the materials, but it is regulated as a function of the use that is made of the material.

On the other hand, if one is talking of the testing methods, these can also vary from one country to another. As an example, the method for determining the resistance to slippage of a stone is different if done in Spain (the pendulum method) to that in Germany (method of the ramp), to that in USA (method of slider).

What Is The Obligatory EC Marked In Europe?

The marked EC indicates that the manufacturer of the product has assured that the harmonised norms have been met. Till now the marked EC in natural stone is obligatory for kerbstones, pavers and tiles for exterior and interior pavements, slabs for facades, tiles for cladding of floors and walls and pieces for manufacture of brickwork , i.e., ashlar walls and similar things.

The manufacturers then need to put in place Control Systems of Production, do initial testing on the products and, with certain frequency, new control tests.

The results of the tests obtained are embodied in two documents: a declaration of Capabilities and the marked EC is put on the products.

As a Producer, What Does One Have To Give To The Clients?

If one is selling within the EU, one needs to give a Declaration of Capabilities of ones products. In other countries one needs to follow the norms that can have effect but, in all cases, it is important to understand that it is always necessary to do testing frequently of the stone materials and this must be available in the form of ' technical characteristics' with at least the most important test results.

What Are The Characteristics Currently Considered Most Important?

In any techcnical data of a stone it is recommended there be information on some of the following tests: resistance to flexion, resistence to compression, water absorption, density and porosity.

There are other important tests but that would depend on the application being made of the stone, which could be tests on slippage, or wearing out in a pavement, or tests of resistance to ice in cold climates.

Now to deal with the ideas of the tests that represent the most important characteristics so as to understand their usefulness.

What Is The Significance Of The Results Of The Most Important Characteristics?

Resistance to Flexibility

Let us say that flexibility is the deformation that can take place in any element in the perpendicular direction to its longitude axis. This type of stress is undergone by tiles or slabs on the facades.

The test is done with a press that keeps increasing the load on the material till its breakage.

Knowing the value of resistance to flexibility is fundamental. A number for resistance of a stone by itself does not indicate that the material is 'better or worse' for a particular application, but one needs to adequately calculate the dimensions.

In natural stone, the values of resistance to flexibility can vary very much from one material to another. For example, some limestones or sandstones can give values from 2 to 3 Megapascals (MPa) and, on the other hand, slates can give values that can go up to as much as 60 MPa, or more.

The following table portrays orientative values of resistance to flexibility for different types of stones:

Resistance To Flexibility (Mpa)	Quartzites	Granites	Marbles	Limestones	Sandstones
LOW	<6 - 9	<5 - 8	<4 - 7	<3	<3
MEDIUM	9 - 20	8 - 16	7 - 15	3 - 6	3 - 6
HIGH	>20	16 - >20	15 - >20	6 - >8	6 - >8

Resistance to Compression

The compression load represents the flattening load, for this the testing is important for stone products that are installed in a big way such as cobblestones or ashlars for walls. The testing is done with a press subjected to loads that flatten it.

As orientation, the following table portrays the values of resistance to compression for different types of stones.

Resistance To Compression (Mpa)	Quartzites	Granites	Marbles	Limestones	Sandstones
LOW	<70	<80	<50	<30	<30
MEDIUM	70 - 150	80 - 150	50 - 120	30 - 100	30 - 80
HIGH	>150	>150	>120	>100	>80

Water Absorption

The capacity of water absorption of a stone is specially important for some applications.

The values of atmospheric water absorption of natural stone can range from almost zero, close to 0% in some marbles and granites, to values of 10% or more for not very dense limestones. The table below shows some common and orientative values:

Water Absorption (%)	Quartzites	Granites	Marbles	Limestones	Sandstones
LOW	<1	<0.3	<0.1	<2	<3
MEDIUM	1 - 3	0.3 - 1	0.1 - 0.8	2 - 7	3 - 10
HIGH	>3	>1	>0.8	>7	>10

There are also products that can seal the pores of the stones. These are chemical and water repellant products aimed at waterproofing.

Density

The density of stone is measured in kgs per cubic metre of material. Greater the density, less is the percentage of porosity and greater the strength and, normally, less capacity of absorption.

Within each variety of rock there can be more or less dense stones, even so one can provide, as an example, the following table of values:

Density (kg/cm3)	Quartzites	Granites	Marbles	Limestones	Sandstones
LOW	<2500	<2500	<2500	<1700	<1900
MEDIUM	2500 - 2800	2500 - 2800	2500 - 2800	1700 - 2200	1900 - 2500
HIGH	>2800	>2800	>2800	>2200	>2500

Porosity

The porosity is closely linked to density: more the pores, less dense is the material, i.e., less weight per unit volume.

The porosity is given in percentage, and can vary a lot from one material to another, from less than 1% till much higher values for very porous stones such as limestones, travertines and similar.

Open Porosity (%)	Quartzites	Granites	Marbles	Limestones	Sandstones
LOW	<0.4	<0.4	<0.3	<1	<1
MEDIUM	0.4 - 1.3	0.4 - 1.3	0.3 - 1.3	1 - 5	1 - 15
HIGH	>1.3	>1.3	>1.3	>5	>15

Resistance to Wearing Out

Wearing out has to do with the traffic over the surface of a tile or pavement.

There are several ways of measuring the wearing out. The American method gives a result in the form of an index ((I_w), other methods provide a result in millimetres.

It is an important characteristic to determine when dealing, for example, with pavements with very high traffic such as shopping centres, train stations, airports, etc.

Resistance to Slippage

It is the capacity of a stone to resist the slippage of a person due to the surface. There are several ways of measuring though the most commonly used is the pendulum of friction, of which one can see the image below:

The great advantage of this method is one can do testing at site, i.e., out of the laboratory. Other methods, such as the German, that of the ramp, or that used in USA, BOT 3000, also result useful to determine this characteristic.

Depending on the country of destination one can observe the requirements. In a general way, in Europe, the values of slippage greater than 35 are considered safe against slipping. If, on the contrary, one measures with the German method, one will determine the type of slipperiness( from R9 to R13). In USA, on the contrary, one measures the coefficient of dynamic friction, with results between 0 and 1.

Name of the Stone

When one talks of the name of the stone one refers to the commercial denomination and its petrographic denomination.

The commercial denomination is the one that is adopted by the manufacturer and supplier. It is common that a stone from the same exploitation be given different names when processed and commercialised by different companies.

The petrographic denomination of a rock is that one which is determined after a petrographic study with the microscope.

To give an example of this, a granite, commercially denominated ROSA PORRIÑO, referring to its characteristic colour, is, petrographically, a biotitic granite. These two names ought to be clearly identified in a data sheet, same as the origin of the material (location of the quarry).

Other characteristics related to the peculiarities of the project:

Each project has its conditions and distinct peculiarities. For example, in external areas where there is risk of frequent snowfall, it is important to to be clear of the resistance of a stone to the cycles of frosting and defrosting. When there is a strong exposure to high temperatures or to important thermal shocks one must determine the changes that take place in the material and, if relevant, the coefficients of thermal expansion of the stone. If the area where the stone is used is close to the sea or to a salty environment, it will also be necessary to judge these aspects.

The table below indicates, as an orientation, the different coefficients of thermal expansion of some natural stones.

Type of Stone	Coefficient of Thermal Expansion
Quartzites	3 x 10-6 to 7 x 10-6
Granites	5 x 10-6 to 9 x 10-6
Marbles	3 x 10-6 to 6 x 10-6
Limestones	3 x 10-6 to 7 x 10-6
Sandstones	2 x 10-6 to 7 x 10-6

What Are The Requirements In a Stone For Pavements?

If one is going to choose a stone for pavements one should take into account the following characteristics:

Resistance to flexibility

Currently whenever big size and slender formats are installed it becomes especially relevant to calculate the adequate thickness of the tile.

That a stone has a higher resistance to flexibility, or lower, does not mean it is a worse material but that, under the same conditions, the one with greater thickness will be installed.

When dealing with cobblestones the resistance to compression will be the most important characteristic.

Absorption of water and porosity

Depending on the degree of humidity in the environment one may need to limit the requisites, it is more important if one is talking of exterior pavings or whether it is in frequent contact with water.

The American norms ASTM establish recommendations for water absorption at atmospheric pressure depending on the type of stone, for example 0.4% for granite and 0.2% for marble.

Resistance to sliding

Limiting the possible slippage of the pavement users is extremely important to guarantee the safety in usage, above all in exterior or interior pavements where there is a risk of liquids spilling over. One needs to fulfil the requisites established in the destination country.

Resistance to wearing

The wearing out that is produced over time due to passage on the pavement surface is not a trivial matter. In some countries limits to resistance to wearing is recommended as a function of usage of the pavement with more or less intensity of traffic.

For Facades What Requisites Should a Stone Have?

When it comes to facades one needs to take into account, generally speaking, the following characteristics:

Resistance to flexibility

For the same reason as in the case of pavements one needs to know the resistance to flexibility to give an adequate dimension to the pieces which will comprise the facade.

Water absorption

In soles of the facades (lower parts) which are in constant contact with water (of the side walks and terraces) one needs to control the water absorption due to capillarity.

Resistance to anchors

It is convenient that for any stone that is going to be installed with anchors in the edges or in the back side testing be done to know the resistance to these types of anchors.

Counter Tops

The countertop is usually a star product of the aesthetically spectacular stones. It is important that the stones that are destined for countertops have:

- With very little or no porosity, close to 0 %, therefore occasionally products are applied to improve this characteristic.

- They are not easily stained: there is a test for this that determines the sensibility to accidental staining of the stone, which can be done with distinct agents of stains in a particular moment, for example, coffee, oils, wine, etc.

- That the thermal shocks do not affect them. Those produced by supporting a very hot plate on its surface.

- That it be resistant to scratching of the possible sharp tools used in the kitchen.

About the Author

Mrs. Eva Portas Fernández is a technical architect and has developed her professional career for more than 15 years in the natural stone industry. She has been Director of Quality in the testing laboratory of the Technological Centre of Granite in Porriño (Spain). Since 2018 she has been an independent consultan (STEINN)t, working on projects of special relevance and with different public sector and private institutions.

Acknowledegements: Thanks to Mr Reiner Krug of the German Stone Association (DNV) for his inputs.

Comparative Stone Quarrying policies in different countries

Q1. What is the period of lease that is awarded for stone mining in your country?

BRAZIL

There is no leasing period. Once the miner is commissioned with a Mining Authorization, he can hold the lease as long as its proved reserves allow him. He initially files at ANN a Mining Plan, with a feasibility study indicating the expected monthly production. If we divide the overall approved reserves by the monthly production we will have the mine lifetime. If the miner does not re-evaluate reserves within this period, his lease will end with the exhaustion of the reserves. Sub-lease is allowed for a maximum period of 30 years.

EGYPT

15 years.

FINLAND

In Finland, quarrying of granite and schist is ruled by the Land Extraction Act, and a land extraction permit and an environmental licence is acquired, while the extraction of soapstone and marble is covered by the Mining Act, and a mining permit and an environmental licence is required. The land extraction permit that is awarded for stone quarrying in Finland is 10, 15 or 20 years.

INDIA

20 years + 20 years.

PORTUGAL

Currently there is no limit. According to the new legislation (not yet published) the duration is 50 years.

RUSSIA

5-49 years.

SPAIN

Depends on the qualification of the resource, which means that small quarries that produce construction materials are authorized until the resource is finished in that area of exploitation or the period estimated in the Project that all that present rock is going to be extracted. After that period can be renewed. In block quarries are granted for 30 years renewable up to 90 years or 75 depending on the area where the quarry is located.

SWEDEN

Between 25-40 years will be granted as concession by the authorities. Contract with landowner signed on same term.

TURKEY

Period of the license is 20 years when first awarded.

Q2. When it comes to renewal of the lease, what is the prevailing policy?

BRAZIL

Since the lease is not subject to renewal, there is no valid policy for that. However, miner cannot stop production without government authorization, needs to file yearly production reports, pay government royalties and follow the environmental plan approved. If he fails to meet these criteria he might get his mining claim canceled.

EGYPT

Renewal is on annual basis. For a 15 years period approval is needed from the Parliament.

FINLAND

Case by case, but usually no problem to get renewal.

INDIA

One needs to apply for renewal, and the process is not very complicated.

PORTUGAL

In practice it is a new licensing. All documentation is identical to an all-new license.

RUSSIA

In case if you want to prolong the lease you have to start he procedures within 6-12 months before the end of lease.

SPAIN

If the renovation does not affect the land in any way, it is relatively simple. A report from the Facultative Director accrediting the reserves, an exploitation and restoration project and urban certification of the land would be presented. If an extension of the work area is planned, it must be submitted to an Environmental Impact Study and a new Environmental Impact Declaration with the problems that may arise, especially in terms of time.

SWEDEN

Full application, similar as for a new one. Water impact has to be analysed and measured. Noise and vibration must be determined. Impact for neighbors e.g. noise, transports. Energy source used and pollution from it. Historical and culture value of the area.
After concession to mine is granted it also includes terms for the annual environmental declaration.

TURKEY

After initial period it is renewed every 10 years. It is a natural right of renewal. However, the quarry site is inspected and also documentation needed, the approvals need to be controlled one more time for the renewal.

Comparative Stone Quarrying policies in different countries

Q3. What are the royalty rates?

BRAZIL

Miners must pay a royalty for the ore production to the government, varying according to the different items. In Brazil this royalty is named CEFEM. For Natural Stones, CEFEM is 1%, gold is 1.5%, Diamond 2%, Bauxite/Manganese/Niobium 3% ...
Besides, in case the miner did not buy the land where the deposit is located, he must pay the landowner a share in the mining results correspondent to 50% of the CFEM due to the government.

EGYPT

19% of selling price ex-quarry.

FINLAND

In Finland, the landowner owns the stone material, and the quarrier makes an agreement with the landowner and pays a yearly rent for him/her plus royalty per quarried/sold m3.

INDIA

The royalty rates depend from state to state in India. For example, in Tamil Nadu it is Rs 3250/m3 (37,4 €/m3), in Andhra Pradesh it is Rs 2500/m3 (28,8 €/m3), and in Rajasthan it is lower, being volume based.

PORTUGAL

Royalty fees are for mining deposits, not quarries.

RUSSIA

Depends upon the region. From 15 000 rubles/hectare to 150 000 rubles/hectare. The current exchanging rate is about 90 rubles/euro.

SPAIN

There is a mine surface canon that is called, which is around 15 - 17 €/ha, but I think it is only for sections C).

SWEDEN

Up to 5% on blockstone selling price value.

TURKEY

Royalty is 4.5% of the value of marble at the quarry pit.

Q4. Is there any difference in royalty rates if the land used for mining is in the forest or in private hands or in government land?

BRAZIL

No. Royalties are due based on the ore production, regardless of geographic location or land property. Firstly, it is important to note that the 1988 Brazilian Constitution establishes the dichotomy of ground and underground ownership, so that mineral resources, whether mining or not, are distinct properties of the ground, for the purpose of exploration and belong to the Federal Government, which can grant the private individual, through observance of legal dictates, the right to research and exploit, guaranteed to the leaser the ownership of the mining product.

EGYPT

No difference.

FINLAND

No, but often the big forest companies demands 100 % use of the left-over stone.

INDIA

For forest land the royalty is higher. For private and government lands the royalty is the same.

PORTUGAL

No.

RUSSIA

We have no such information.

SPAIN

No.

SWEDEN

Royalty paid to landowner and negotiated individually but no difference depending on ownership, more related to geographical area.

TURKEY

No. Flat rates apply if it is rented from the forestry or the government lands. In the case of private land, negotiation has to be done with the owner. If no agreement is reached, there are procedures which all confiscation by the license holder.

Comparative Stone Quarrying policies in different countries

Q5. Are there any further taxes or rebates or concessions for exports of blocks?

BRAZIL

All exports are exempt of duties regularly paid by domestic operations, like VAT (ICMS), Industrialization Tax (IPI). No additional duties are due for the export of blocks.

EGYPT

Export tax is 25 $ / ton only for blocks. No tax for slabs.

FINLAND

No.

INDIA

No concessions.

PORTUGAL

No.

RUSSIA

No. But we do not pay any additional taxes and fees when export blocks.

SPAIN

No.

SWEDEN

No.

TURKEY

Corporate tax is applied on any domestic companies operating inland.

Comparative Stone Quarrying policies in different countries

Q6. What are the environmental issues usually looked into by the authorities? Is there any public hearing?

BRAZIL

Stone quarrying affects primarily deforestation, soil and water contamination, scenic alteration (visual impact) and erosion. Noise might be a secondary issue that could affect nearby communities. As most of the quarries are located in country zones, this issue has minor impacts and have less importance when it’s about commissioning by environmental agencies. Stone quarrying is not considered a high potential environmental pollutant, so quarriers apply for a simplified environmental clearance, which does not demand a previous public hearing for approval.

EGYPT

Only applies for protected areas. There is an extra fees.

FINLAND

-Noise, dust, vibration, waters, wastes, left-over stones.
-Public hearing case by case, not often.

INDIA

There is public hearing and usually the authorities ensure that public utilities (residence, schools, etc.) are not in the proximity.

PORTUGAL

Companies with explorations equal or above 15hec, with productions above 200,000 tons / year, and / or with others quarries within 1 km are subject to Environmental Impact Study. Yes, this procedure is subject to public consultation. In this scope of the EIA many aspects are evaluated: landscape, fauna and flora, water resources, noise, dust, vibrations, heritage, soil, socio-economics, etc.

RUSSIA

The quarry owner has to submit Project of sanitary-hygienic zones and recultivation of quarry. Public hearings in case of need according to national legislation.

SPAIN

For an environmental impact study, they ask for reports from the environment, heritage, water authority, territorial studies, environmental associations, city hall and others (for example if it is near the sea or the coast). There is always public exposure for a month.

SWEDEN

Noise, vibrations, water quality and water flow implications is part of the application topics. Also any historical or cultural values are under scrutiny. A hearing take place after an initial application has been issued but normally only different authorities take part not the public. When our initial application is issued, we must however inform neighbours up to 500 metres from the quarry border.

TURKEY

Environmental issues are specific to the individual quarries. Depends on the place where the quarries operate (eg. specific type of forest, lake, historic town, park, etc.). Hearings are independently made for each case if there is a dispute.

Q7. For how long is the environmental clearance valid? How often do you have to submit returns to the authorities?

BRAZIL

It varies depending on the environmental plan, but it goes from a minimum of 4 years and maximum 10 years. In Espirito Santo, where most of the stone production comes from, the environmental clearance is currently valid for 5 years and might be renewed indefinitely, as long as the miner holds the Mining Authorization and follows the guidelines established in the environmental plan. Miners have to file the renewal up to 120 days before the validity of the Clearance.

EGYPT

Environmental clearance is given on yearly basis.

FINLAND

- As long as the land extraction permit.
- Every 1-4 years, depending on the choice of the authority.

INDIA

20 years.

PORTUGAL

The environmental assessment is carried out every 3 years. They also present an annual report. There are also EIA descriptors that can restrict the periodicity of some parameters, but these situations / monitoring are determined on a case-by-case basis.

RUSSIA

Till the end of lease. In case of changings in project of the quarry additions to the environmental clearance should be provided.

SPAIN

The duration of the Environmental Impact Statement or the Environmental Report is while the operation is being exploited or the same conditions are maintained as those that were subjected to the Environmental Impact Study. Obviously, if unaltered areas are to be affected, a new environmental authorization must be obtained. Every year, together with the Work Plan, an environmental follow-up report must be presented where the most important aspects of this subject of the quarry and those specific ones ordered in the Environmental Impact Declaration are summarized.

SWEDEN

The concession gives us an environmental clearance to mine which is valid for many years between 25 to 40. Environmental declaration shall be submitted on a yearly base terms are issued when concession is given.

TURKEY

After the first clearance and “environmental effects study“, if it is obtained positively it is checked by the official body regularly.

Q8. On average, how much time does it take to obtain environmental clearance in your country?

BRAZIL

It usually takes between 1-2 years after the Environmental Plan is filed in the government agency.

EGYPT

6 to 8 weeks.

FINLAND

1/2 to 1 year

INDIA

Environmental clearances take anywhere between 6 months to one year.

PORTUGAL

In the best case scenario, 5 years.

RUSSIA

6-12 months including all approvals.

SPAIN

The environmental authorization between 6 months and a year if no remedial action has to be taken which in that case could easily double the time. The authorization of a quarry between 3 and 5 years.

SWEDEN

To get a concession between 1 and up to 5 years depending on the case. If limited water implication can be proved the regional authority will decide and time is normally between 1 and 2 years. If water implication is deemed to be more severe the application will be moved to a special court and time will be longer at least 2 years and up to 5 years.

TURKEY

Generally speaking, six months to eighteen months.

Q9. Is there any pollution control clearance required in your country? If so, how are they structured?

BRAZIL

No, in Brazil the only control over pollution are the rules that the company need to abide to, based on the Environmental Plan approved by the agency.

EGYPT

No pollution control.

FINLAND

- Water monitoring (sampling 2-4 times a year, nitrogen the most important parametre), the authority demands it in the permit and the quarrier (with consultant) draws up the plan. The consultant executes the monitoring.
- Noise, dust, vibration if needed, seldom compulsory.

INDIA

Pollution control clearance is required.

PORTUGAL

This type of monitoring is defined in the quarry plan, involving control of air quality (dust), soil and water, which are mandatory (those provided for in point 6).

RUSSIA

All pollutions are under control.

SPAIN

Every year a study of dust and environmental noise should be carried out and between 2 and 4 controls per year of the conditions of the water to be poured should be made.

SWEDEN

Yes, test has to be carried out annually depending on requirement in the concession. We often must take water samples to be tested, noise and vibration from equipment and from blasting must be performed. All test to be inserted in annual environmental declaration.

TURKEY

Pollution control measures are assesed and decided in the “environmental affects study”. Therefore, positive result needs to be achieved through this study so as to get the green light.

Comparative Stone Quarrying policies in different countries

Q10. What is the average number of people employed in a quarry in your country?

BRAZIL

Based on Sindirochas, 75 people is the average number of employees in natural stone quarries in Brazil.

EGYPT

Average is 15 to 25 people.

FINLAND

5 - 10.

INDIA

50 to 100 people.

PORTUGAL

Statistical data: Taking into account that in 2019 there were 2760 employees in 337 establishments, on average there will be 8 employees per quarry. However, it is estimated that between 10 and 15 workers per quarry.

RUSSIA

From 5 workers in a small quarry up to 100 workers on big quarries (like our Vozrozhdenie quarry).

SPAIN

About 8 - 10.

SWEDEN

5 people.

TURKEY

There is no standard. Half dozen to few hundred of employees, depending on the quarry.

Introduction

In recent years 'Sustainability' has become important, of the highest priority in any economic decision making and activity,and an almost obligatory company philosophy for any enterprise. However, for anyone trying to understand Sustainability, it is usually not easy, far too often any explanation or discussion lapses into technical data or use of different confusing terms.

This WONASA Guide is an attempt to explain Sustainability in a way that is easily understandable to the people working in the natural stone industry. Needless to say, anyone needing to understand and act on this topic in a detailed manner, will need to consult other sources, reports and studies.

WHAT IS SUSTAINABILITY?

Sustainability defies a simple, clear cut definition. In fact, there are different definitions and differences in the way it is understood by people, which is why there is often so much confusion in discussions and debates.

One widely used, and, a very general definition of Sustainability, is the one made by the UN World Commission on Environment and Development, which defines Sustainability as being: 'meeting the needs of the present without compromising the ability of future generations to meet their needs'. Sustainability, when understood through this very broad angle, is very about the future and not just focused on the present.

Another definition: "In essence, sustainable development is a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development, and institutional change are all in harmony and enhance both current and future potential to meet human needs and aspirations.” Brundtland Commission in 1987.

Yet another definition of Sustainability with a different choice of words, is in terms of human, social, economic and environmental effects – and these are often considered by many experts to be “The Four Pillars of Sustainability”.

WHY IS SUSTAINABILITY CONSIDERED IMPORTANT?

Global warming and the resulting harmful effects have now made Sustainability a top priority of mankind during the last few years.

Sustainability is supposed to have benefits both in the short-term and the long-term. The underlying assumption behind Sustainability is that to maintain the Earth’s ecosystems the world has to make more sustainable choices and stop functioning in the current way. The argument for sustainable choices lies, in practical terms, in the need for clean air and nontoxic atmospheric conditions, growth of resources that can be relied upon, water quality, cleanliness, etc.

WHAT ARE THE FEATURES OF SUSTAINABILITY?

There are several principles of Sustainability, and there is no unanimity on this among experts. However, the following principles are usually considered to be the defining features of Sustainability:

a).Circular economy. Aiming for resource efficiency through better waste management.
b).Energy Savings.
c).Sustainable material choices.
d). Life Cycle Assessment (LCA).
e).Environmental Product Declaration (EPD).
f).Constant research and innovation.
g).Corporate social responsibility.

THE LANGUAGE OF SUSTAINABILITY EXPLAINED

1. What is Carbon Footprint?

The total amount of greenhouse gasses produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (tCO2).”

2. Carbon Neutral

Carbon neutral means a balance between emitting carbon and absorbing carbon from the atmosphere in carbon sinks.

Carbon Neutral is NOT the same thing as Carbon Net Zero which implies making changes in economic activity to reduce carbon emissions to the minimum possible level and, in addition, offsetting to compensate for the essential emissions that are left after all reduction methods have been taken.

3. Embodied Carbon

Embodied carbon refers to all the greenhouse gas emissions associated with production of products. For construction, these include the complete cycle of quarrying, transport, processing, installation, etc. Sometimes, this is also termed as "Carbon to Gate" embodied carbon in the construction industry. Sometimes people will refer to it by calling it "supply chain carbon".

4. Life Cycle Assessment (LCA)

Life cycle assessment(LCA) can be defined as "systematic analysis of the potential environmental impacts of products or services during their entire life cycle" ( Source- Sphera). It means evaluating the potential environmental impacts throughout the entire life cycle (quarrying, processing, use and end-of-life phases). LCA also includes the suppliers, waste product management, production of raw, auxiliary and operating materials, and disposal. It covers all relevant inputs, (for example, water, land use, etc.), and it also includes emissions into the air, water and soil. For evaluation of ecological impact and comparisons many studies use a time period of 50 years for life-cycle phases, from production to usage.

Also considered in the LCA is any process done during the installation or use period of the product, such as the application of sealers during the life cycle of a countertop

5. Circular Economy

The European Union defines it quite well : Circular Economy is a model of production and consumption which involves sharing, leasing, reusing, refurbishing and recycling existing materials and products as long as possible. At its core the Circular Economy is all about reducing or minimizing waste, and extending the life cycle of products.

6. LEED (Leadership in Energy and Environmental Design)

In the USA, the Green Building Council developed the LEED System in 1994, it is a green building rating system. LEED provides a framework for efficient and cost saving green buildings. To date the LEED system does not use a complete life cycle assessment of the actual environmental performance of a building, it does a specific rating to all materials and building products that need to be transported less than 800 km to a construction site.

7. Environmental Product Declaration(EPD)

An Environmental Product Declaration (EPD) is an independently verified and registered document that communicates transparent and comparable information about the life-cycle environmental impact of products in a credible way.

However, there is also a self-declared EPD process, so an EPD may not always be an independently verified document. Since these documents can be costly producers may have a hybrid system of verified EPD for higher volume products and some self-declared ones for lower volume products.

An EPD is a so-called type III environmental declaration that is compliant with the ISO 14025 standard. A type III environmental declaration is created and registered in the framework of a programme, such as the International EPD System

Environmental Product Declaration (EPD)

It is important to understand that there are essentially 3 types of EPDs.

1. Average EPD. It refers to an EPD that covers similar products made by the same manufacturer. Similar products from a single or several manufacturing sites can be declared environmental performance as average results.

2. Industry-wide EPD. A generic or industry-wide, EPD is one that is released by multiple manufacturers, often through a trade association, to publish the average footprint of the entire industry. This EPD does not cover individual products (a specific type of stone, for example), it basically accounts for the average product in a specific sector. A sector EPD declares the average product of multiple companies in a clearly defined sector in a clearly defined geographical area.

3. Product-specific. This EPD is the more rigorous in the sense that it covers a single product from a manufacturer. As an example, there can be an EPD for a specific stone with 2 cm in thickness located in a particular geographical location, and another stone with 3 cm in thickness.

Why is EPD becoming important?

The objective is to encourage the use of materials that have socially and economically preferable impacts on the planet and EPD is a way of life cycle assessment and a standardised way of quantifying the impact of a material on the environment.

How is EPD relevant to the natural stone industry?

When natural stone is being used mainly for decoration purposes (floorings, kitchen countertops, bathrooms,etc. in private homes) in small volumes, common sense dictates that EPD will normally be irrelevant as a criteria in decision making. Aesthetics and mechanical properties of the stones are likely to be more important considerations in these cases. Most likely the home owner would be creating more carbon emissions when driving in the car from his home just to go to the office, or to the supermarket.

But EPD becomes relevant as a building material, to be used in projects, in public or commercial buildings, where the measurement of ecological performance of different materials are an important criteria for architects and specifiers who, increasingly, are bound by the terms of the project, to consider life cycle assessments. Sooner or later, having an EPD number may end up being obligatory for a natural stone to be considered as an option in public procurement and in the private sector projects.

If any stone is being frequently used for projects, then it is advisable to get the EPD done for that stone, especially in 2 cm and 3 cm thickness, because these are the most common formats. If a stone is used frequently in exterior pavings in thickness such as 4 cm or more, then the EPD for that format could be obtained. For natural stones used principally for decoration purposes in small quantities, it is hard to understand why an EPD is necessary for that stone.

From different studies conducted in the last few years, in the case of natural stone life cycle assessment results have been excellent. As we all know, the primary energy consumed in extraction and processing is very low in the production cycle. Those who are working in the natural stone industry intuitively understand this, after all natural stone has evolved over tens of million years (when not hundreds of million years) in its creation, and no energy is needed to create it, as is the case with most alternative materials. Natural stone comes out of the quarry as a semi-complete building material, and the only energy needed thereafter is in its processing and transport, and in installation.

How is EPD measured?

To calculate the indicators required for an EPD of a natural stone, the LCA Consultant will ask principally for the following information:

How and where the stone is obtained and its related resource use such as energy and water consumption

The distance and transport mode of the stone to the plant

Energy and resource use in production

Delivery transport to customers

End of life options available to the stone when discarded.

Based on this information, the inventory of the whole product life cycle is obtained and these are then turned into environmental indicators by mainly using software tools.

How do the EPDs of natural stone compare with other alternative materials?

In 2019, the DNV (German Natural Stone Association) commissioned a study by the Institute of Construction Materials at the University of Stuttgart, which compared the ecological and economic impacts of different floor coverings from the production to the use phase.

The data was collected from existing environmental product declarations (EPD) issued by the various building material manufacturers. Natural stone floor coverings predictably achieved very good life-cycle assessment results, due to the low primary energy demand of the stone.

A comparison of all floor coverings showed that those produced from natural stone cause a significantly lower environmental impact in their production, installation and use than large-format ceramics, carpets, PVC, laminates, and parquet.

In the category of global warming potential (GWP) impact, the production and utilization of floor coverings using natural stone tiles display significantly lower CO2 equivalents than the production and use of other covering materials.

Some examples of CO2 emissions comparisons (Natural stone from Finland)

Comparison of CO2 emissions (DNV Study)

WHO DOES THE EPD STUDIES?

In many countries there are recognised entities which have the expertise to conduct these studies and their certificates should be valid internationally.

TO SUMMARIZE, WHY NATURAL STONE?

1. No energy is needed for creation of natural stone, that process has evolved over millions of years. Energy use is for extraction and processing.
2. It is a reusable product.
3. It has demonstrated its durability over centuries.
4. There are no pollutants in natural stone, it is an inert material and can be returned to the natural material cycle easily.
5. Natural stone contains no harmful substances.
6. It is fire resistant.
7. Water recycling in the fabrication process.
8. Environment green program is nowadays mandatory in most countries before the extracting companies get licence to extract natural stone.
9. There is low CO2 emission in the fabrication process.