the natural choice - Brachot-Hermant

the natural choice 

From the quarry to the yard. That is the standard route of natural stone. And that 

is the route that Brachot-Hermant understands better than anyone else. 

The purchase department of Brachot-Hermant is familiar with the most important 

quarries across the world. We provide a guaranteed transport and delivery of 

blocks at the most competitive prices. We monitor quality with great attention 

to detail. And, of course, we also cut stone from our own quarries in France, 

Norway, India and Brazil. 

Brachot-Hermant is a leader in the entire production process. The skilled staff 

and ultra-modern machinery in our four production plants ensure excellent 

quality. In addition, our finishing machines – particularly those for Anciento , 

Calibrato and Letano – are amongst the very best on the market. 

With 12 depots at locations in Belgium, the Netherlands, France, Great Britain 

and Poland, Brachot-Hermant is always close to its customers. Hundreds of 

different products are held continually in stock and are available for almost 

immediate delivery. Professional logistical management and a modern fleet of 

lorries ensure that we can deliver to the very furthest corners of Europe. 

An excellent range, an extensive stock and an unbeatable balance between 

price and quality: for all these reasons, Brachot-Hermant is your natural choice 

for natural stone. 

In this natural stone catalogue, you will become acquainted with our outstanding 

selection of natural stone. Enjoy your read and, above all, enjoy the beauty of 

natural stone. 

In this Natural Stone 

Catalogue 2006/7 you will 

fi nd hundreds of “ordinary” 

and exotic natural stones 

from all over the world. There 

is an enormous choice in 

granites and marbles. Of 

course you will also fi nd 

limestone, basalt, slate and 

bluestone. 

Dirk Van Overberghe, 

Managing Director Brachot-Hermant 

Philippe Vaernewyck 

Managing Director Brachot-Hermant 

1

more than 100 years of 

craftsmanship 

brachot-hermant 

In 1901 Victor Hermant transformed an old water mill in 

the Belgian town of Hour-Havenne into a production 

plant for marble. Water was diverted from the river Lesse 

to power the cutting and polishing machines. The fi rm 

gradually expanded and in 1906 opened a branch offi ce in 

Brussels (B). 

A further important step was taken in 1934, when Victor 

Hermant – together with his two widowed sisters – founded 

the new limited company Brachot-Hermant-Waucquez. 

A new depot was opened in Ghent (B), so that the new 

company was now active in both the Dutch and Frenchspeaking 

parts of Belgium. 

The next wave of expansion came during the 1970’s: a new 

production facility in Hour-Havenne was followed by a 

new sales facility in Sint-Denijs-Westrem (B). The product 

range was extended to include granite. The machinery was 

thoroughly updated. Activity on the international market 

was expanded. Branches were opened in several European 

countries and covered stock areas were established 

(the Netherlands, France, Great Britain and Poland). 


2


In 1988 Brachot-Hermant moved from Sint-Denijs-Westrem (B) to the industrial estate in 

Deinze (B). A new cutting shed for marble/granite and new polishing/tiling machines 

were taken into operation: investments which allowed Brachot-Hermant to consolidate its 

leading position in the domestic market. 

Brachot-Hermant since 1901 

At the same time, considerable resources were also devoted to further international 

expansion. Branches were opened in a number of European countries and in China. 

A brand-new production plant was set up in India, plus investments in various quarries 

across the globe. 

3

natural stone 

from the four corners 

of the world 


There are many thousands of quarries in the world. 

Some are small. Others are large. Some produce 

mass consumption products, such as gravel and chalk. 

Others produce more specialised stone products, such 

as granite, marble, basalt, slate, etc. The exploitation of 

a natural stone quarry requires a great deal of technical 

know-how. It also requires the use of heavy machinery 

and equipment (a rough block of natural stone can easily 

weigh up to 45 tons). 

The quarrying of some stone types takes place in extreme 

climatic conditions: quarries near the equator can be hot 

and wet, whereas the most northerly quarries can often be 

covered by ice and snow. But the result is well worth the 

effort: beautiful natural stone, which enhances the quality 

and comfort of all our lives. 

Brachot-Hermant is fully at home in this world of stone. 

With more than 100 years of experience, its great technical 

expertise and its dedicated and knowledgeable team of 

salesmen, it can offer customers a range of services that 

are second to none. Moreover, its ownership of quarries in 

Norway, France, Brazil and India allows Brachot-Hermant 

access to top-quality stone at source. 


4 

New facilities in China, under the expert leadership of 

Belgian managers, have made available a new range of 

Far Eastern materials, all carefully checked for quality 

prior to shipment. In this manner, we hope to provide 

nature’s finest products at the very best prices. Yet another 

reason why Brachot-Hermant is your natural partner for 

natural stone.


LARVIK GRANITE by Brachot-Hermant 

Natural stone can be found in each of the seven continents: from the icy Labrador 

of Norway to the blood-hot African Red of South Africa, from the sultry Café Brown 

of Brazil to the mysterious Shivakasi of India. Millions of years were necessary for nature 

to give each of these stone types its own specifi c texture and colour. This is what makes 

every slab and every tile unique. 

5

achot-hermant 

at home 

in Europe – and the world 

Stone quarry 

Covered stock area 

Showroom 

Production 

Sales office 


6


BRACHOT-HERMANT headquarters at Deinze (B) 

From its headquarters in Belgium, Brachot-Hermant has developed during the last 30 

years into an international company of considerable standing. With its own depots 

in Belgium, the Netherlands, France, Great Britain and Poland. With its own sales teams 

in Germany, Italy and China. With factories in Belgium, Poland and India. With quarries in 

Brazil, India, Norway and France. 

In particular, the depots and the national sales teams ensure that close contact is kept 

with local markets. This gives Brachot-Hermant the opportunity to react quickly and 

professionally to the specific needs and wishes of different regions. In addition, this 

international dimension allows the company to closely monitor cross-border trends in 

‘living’ and ‘life style’, so that our range of products is carefully attuned to the demands 

of our customers. 

7

four ultra-modern 

production plants 


With four production plants (two in Belgium, one in 

Poland and one in India), Brachot-Hermant can 

boast an impressively large production capacity. Taken 

together, the four sites represent a working area of some 

65,000m 2 . 

Thanks to its hyper-modern machinery, Brachot- Hermant 

is able to market stone in eleven different types of 

finishing: polished, ground, honed, sandblasted, flamed, 

bush- hammered, chiselled, taille ancienne, frost flowers, 

Anciento and Letano . 

Our high-performance, high-technology production system 

ensures that we are able to offer our customers in the 

specialist natural stone and tile trade a significant added 

value. In particular, the fact that production is concentrated 

in our own hands at several points around the world allows 

us to guarantee maximum quality, to meet our delivery 

deadlines punctually and to respond flexibly to the needs 

of the market. 


8


Production plant at Deinze (B) 

Our cutting facilities house frame saws, diamond circle saws, diamond wire saws 

and multi-circle saws. These are supplemented with polishing machines, flame and 

hammering machines, an Anciento line and a resin line. Brachot-Hermant possesses 

several different production lines for the manufacture of tiles and a separate production 

line for the manufacture of skirtings. The production plant in Deinze (B) even has a 

calibration machine, which allows the calibration of fi nished stone slabs to the same 

maximum size as the rough stone block. 

9

an extensive stock 

of blocks, slabs and tiles 


On an average day a total of 15,000 tons of natural 

stone is ‘moved’ (incoming and outgoing) through 

our storage facilities. The efficient control of hundreds 

of different types of natural stone, combined with the 

wide range of different finishings and a strict timetable 

of deliveries, demands specialist expertise and excellent 

process management. For this reason, the Production and 

Administrative Departments have at their disposal the very 

latest logistical software. 

All staff in the storage facilities are thoroughly trained to 

receive and dispatch goods/materials safely and efficiently. 

To allow Brachot-Hermant to pursue a policy of just-in-time 

deliveries, the company possesses its own fleet of lorries. 


10


At Brachot-Hermant ‘stock’ is not just a word: it is a concept. Our customers can 

choose from a permanently available supply of some 200,000 m 2 of slabs and 

tiles and approximately 12,000 m 3 of blocks. In Deinze (B), but also in Hour-Havenne (B), 

Poland and India, hundreds of blocks of granite, marble, blue stone, slate, etc. from all 

over the world stand ready for immediate processing and shipment. These blocks represent 

a sawn surface area of 300,000 m 2 . 

11

achot-hermant 

the Stone Gallery, a source of 

inspiration 

Thanks to Stone Gallery, Brachot-Hermant has a modern 

extensive showroom where you can peacefully 

discover a comprehensive range of granite, marble, limestone, 

slate, basalt and bluestone. You are dipped in the 

fascinating world of natural stone where we take you on 

a journey to stone quarries of the icy North and the sultry 

South. 

But there is more: in our extensive covered stocks, you can 

choose your own unique slab(s) of natural stone. With the 

Unicity Card, you then contact your natural stone mason 

or expert, who will purchase and treat the slab(s) or tiles of 

your choice. 

Also discover the exclusive Natural Art Collection in Stone 

Gallery, unique in Europe. 


12 

Stone Gallery 

E3-laan 86/92 

9800 Deinze (B) 

tel + 32 (0)9 381 82 82 

fax + 32 (0)9 380 16 55 

info@brachot.com 

www.brachot.com


Opening hours 

Monday to Friday from 09:00 to 18:00 non stop 

Saturday from 09:00 to 12:00 

Closed on Sunday and holidays 

Entrance to Stone Gallery is free for everyone. 

13

achot-hermant 

types 

of natural stone 

Natural stone is a collective name for thousands of 

different types of stone, found and quarried throughout 

the world. The appearance and the characteristics of 

natural stone are determined by the manner in which the 

stone was formed: by rivers, by volcanoes, by tectonic 

folding (mountains). 

GRANITE 

Each natural stone is unique, because no two places on 

earth have precisely the same geological composition 

or experience precisely the same geological forces. This 

means that natural stone of the same type can also differ 

widely. 

MARBLE 

For commercial purposes, natural stone is divided into 

several large groups: granite, marble, limestone, basalt 

and slate are the most important. Alongside this commercial 

classification, there is also an alternative scientifi c 

classification, which is divided into three categories: 

magmatic rock, which was created by the cooling of liquid 

magma; sedimentary rock, which was created by the 

compression of loose fragments of existing stone or by 

the deposition of lime particles in water; and metamorphic 

rock, which was created by the transformation of existing 

magmatic or sedimentary rock under high temperature 

and/or pressure. 

LIMESTONE 

BLUE STONE 

BASALT 


14 

SLATE


GRANITE 

The large group of the granites consists largely of 

magmatic rocks which were formed by the cooling 

of magma deep in the earth’s crust. Their outward 

appearance is usually dappled. Some granites are 

also metamorphic in origin, having been created by 

the transformation of existing magmatic rock under 

high pressure (for example, during the development 

of mountain ranges). These metamorphic granites 

are typical for their variegated colouring and their 

flamed structure, which makes every individual 

tile/slab unique. All the granites are renowned for 

their outstanding technical qualities. 

MARBLE 

The group of the marbles contains both 

metamorphic and sedimentary rocks, all of which 

are composed of calciferous particles (calcite). 

Marble is a relatively homogenous and compact 

natural stone. Because it is relatively easy to work, 

but also because of its wide variety of different 

colours (red, white, pink, etc.), it has found many 

applications in the building industry: floors, 

staircases, fireplaces, etc. 

LIMESTONE 

Limestones are sedimentary rocks created by the 

accumulation and compression of fossils and/ 

or stone fragments, such as quartz and calcite. 

The WHITE STONES also consist of compressed 

accumulations of fossils and/or calcite fragments, 

with a texture which is soft and easily workable. 

Certain types are suitable for both indoor and 

outdoor use. The majority of these limestones cannot 

be polished and are delivered with a lightly honed 

finish. The best known examples are the French 

white limestones, but other high quality types are 

available from Portugal, Turkey, etc. These types 

can be used for flooring, fi replaces, statues, etc. 

BLUE STONE 

Blue stone is a dark and compact limestone, 

available in many different fi nishings (from polished 

to rough worked). This specifi c limestone was 

created by an accumulation of fossil material in 

a particularly dark ground sort. In addition to the 

famous Belgian Blue Stone, stone of this type is 

also quarried commercially in Vietnam and Ireland. 

Blue stone is suitable for staircases (indoors and 

outdoors), fi replaces, doorsteps, etc. 

BASALT 

Basalts are magmatic rocks, created by the cooling 

of liquid magma on the earth’s surface. Because 

this cooling was relatively rapid, the minerals in the 

rock had little time to complete the crystallisation 

process. This has resulted in a fi ne-grained 

appearance. In general, basalts are non-porous, 

hard and capable of fi nishing in several different 

manners. Their uses include flooring (indoors and 

outdoors), wall-covering, etc. 

SLATE 

There are many different types of slate, dependent 

upon the clay from which they were formed. Slates 

are highly layered in structure. This gives the 

surface a ‘split’ appearance, but a honed fi nishing 

is also possible. This makes the slates suitable for 

indoor and outdoor flooring, and also for use as wall 

covering. 

15

choosing the correct 

natural stone 



16 

colour 

Every tile, every object in natural stone is unique, by virtue of the 

natural manner of its creation. The colouring is also 100% natural 

– a colouring formed by the different shadings of the mineral 

elements of which the stone is comprised. There is no such thing 

as ‘identical’ with natural stone! Colours can even vary within the 

same quarry, thanks to the differing geological composition in the 

different strata. Moreover, this colouring can be used to create 

various types of effect: lighter colours make a space seem larger, 

whereas darker colours have the opposite result. 

texture 

The origin of the stone and its geological history are the main 

determining factors for texture. Take, for example, granite and 

basalt. Both stone types were formed from magma, but granite 

has a completely different geological history than basalt. 

Consequently, the two stones look very dissimilar. Granite has a 

mottled appearance, due to the fact that its mineral grains – in 

various sizes – can clearly be distinguished. In contrast, basalt 

appears to be very finely grained, due to the fact that its minerals 

had insufficient time to crystallise fully. Marbles have a generally 

‘softer’ appearance, with typical ‘veined’ markings. Limestones still 

show traces of the fossilised shells and corals from which they were 

made. 

size 

Size can also play an important role in the choice of natural 

stone tiles. Large format tiles give an impression of greater space. 

Smaller tiles have the opposite effect. Natural stone for use on 

floors and walls is available in square tiles and random lengths. 

For surfaces which are often exposed to changes in temperature 

(such as flooring next to large windows or on an outdoor terrace), 

it is advisable to work with square tiles with a maximum size of 

40 cm x 40 cm (also see technical specification TV 213 of the WTCB 

- Wetenschappelijk en Technisch Centrum voor het Bouwbedrijf - 

he greatest diversity 

Tin natural stone 

is to be found in the 

granites and marbles, 

where there are literally 

hundreds of dif ferent 

colour and texture combinations. 

The lime stones, 

including the blue stones, 

usually show some traces 

of their fossil-based origin. 

The list is completed by the 

clay-based slates and the 

magma-based basalts. This 

natural stone catalogue will 

offer you a selection of the 

very best types of stone 

to be found within each of 

these categories.

Belgian Building Research Institute). The use of random lengths in such circumstances 

is not recommended. The thickness of the natural stone is generally determined by the 

weight it will be required to bear and by the level of stability it must provide. Specially 

calibrated thin tiles are available for renovation work (where thickness and weight can 

sometimes play a more crucial role) and/or for work where the stone must be glued into 

position. 

finishing 

The surface finishing of the natural stone is a key factor in determining its final 

appearance, but also plays an important role in helping to decide which material should 

be used for which application. For outdoor use, there is tendency to opt for a ‘rougher’ 

finish (because of its enhanced anti-slip qualities). This also means that the stones are 

generally lighter in colour. For decorative interior work, the choice usually falls on one 

of the polished finishes, since these highlight more clearly the colour and structure of 

the stone. Remember, however, that rougher finishes are more difficult to maintain, whilst 

polished finishes (particularly in busy locations) can quickly become scratched. 

technical characteristics 

To a large degree, it is the composition and characteristics of the natural stone which 

are crucial in determining the final choice. Acid resistance can also be relevant in 

certain circumstances (e.g. for use in kitchens), as can water absorption (e.g. for use in 

bathrooms). These characteristics are directly related to the composition of the stone in 

question. Similarly, not all natural stones can be used for the installation of an outdoor 

terrace, since not all natural stones are frost-resistant. By the same token, some natural 

stones cannot be used for floor work, since they are not sufficiently hard to cope with 

the wear-and-tear which they will inevitably receive. 

terraces 

For outdoor terraces, natural stone tiles are laid directly onto a surface which 

can become frozen in winter. Consequently, terrace tiles must meet the strongest 

frost-resistance criteria. Moreover, because terraces are frequently subjected to 

high degrees of thermal stresses (cooling down at night and warming up during 

the day, resulting in repeated expansion and contraction), it is not advisable 

to choose random lengths for terrace work. Square tiles with a maximum size of 

40 cm x 40 cm are a much better option. It is also advisable to allow the joints to run 

straight through and not to work in a cross pattern. Don’t forget to allow a sufficient 

number of expansion joints! Terrace tiles must also be anti-slip and this suggests the 

use of one of the rougher finishes, such as flamed or bush-hammered. The thickness 

of the tiles will generally be determined by the stability of the foundation layer, the 

nature of the fixing and the weight to be carried. With a traditional fixing method and a 

normal load- bearing capacity (for people only, not cars) a thickness of 2 cm will usually 

suffice. A greater thickness is recommended for fixing on raised tile laths. For driveways 

a thickness of 5 cm or more will generally be used. 

17

interior floors 

Floors in living rooms and halls are intensively used. A polished finish will wear out more 

quickly than a honed surface. For halls, it is also important to place a doormat, so that 

the majority of outdoor dirt, grit, etc can be kept off the floor, thereby reducing abrasive 

damage. Remember that a natural stone floor laid above floor heating will be subject to 

increased thermal stress. For this reason, it is not advisable to choose random lengths 

for this type of work, but instead to use square tiles with a maximum size of 40 cm x 

40 cm and run-through joints. For larger surfaces, make sure that you allow sufficient 

expansion joints. The use of long tiles placed parallel to the walls in a narrow hall can 

help to create a further ‘narrowing’ effect. The use of long tiles placed at right angles 

to the walls in a narrow hall can help to create a ‘broadening’ effect. Acid-resistant and 

water- repellent tiles are recommended for use in kitchens, with low- absorption tiles for 

bathrooms and toilets. 

kitchen top 

For a kitchen top account must be taken of an increased risk of staining (from products 

with a high acid content, such as vinegar and lemon juice) and scratching (from repeated 

and intensive use). For this reason, it is advisable to choose a natural stone which 

is acid- and scratch-resistant, with a limited porosity and absorption. This suggests the 

choice of a granite-type stone (hard, with a limited porosity, acid-resistant) instead of a 

marble or limestone (softer, low acid resistance). For all stone types, it is advisable to 

impregnate the kitchen top with a water- and oil-repelling product. 

kitchen floor 

The kitchen is the room in the house with the most ‘coming and going’. For this reason, 

there is an increased risk of damage to a polished kitchen floor. A rougher, lightlyhoned 

finish is therefore a better option. Again it is advisable to pre-treat the floor with 

a water- and oil-repelling product. 

bathroom 

For all bathroom applications it is necessary to take account of the high relative 

humidity. For this reason, it is advisable to choose a non-absorbent natural stone. The 

dampness of the bathroom environment also means that careful attention must be paid 

to the installation of the stone. Afterwards, both the stone and the pointing must be 

treated with a water-repelling product. 

For showers it is essential to ensure that the construction is fully watertight (particularly 

around the basin and the taps). To avoid scaling when marble-type stones are used, it 

is recommended to use only acid-free cleaning products. 


18

athroom floor 

In bathrooms, it is important to pay attention to the anti-slip qualities of the floor. Polished 

natural stone is slippery, particularly when wet. It is therefore strongly recommended 

to choose a non-polished floor (for example, lightly-honed, Anciento or Letano . A 

further preventative treatment to make the floor fully water-repellent will enhance the 

life-expectancy of your floor. 

cladding 

Natural stones for use on facades must be fully frost-resistant. However, because the 

cladding is not in direct contact with a frozen surface, there is a greater choice of stone 

types than for terraces. Remember that porous natural stones will become dirty more 

quickly than the more compact types. In coastal areas, it is also necessary to take 

account of the abrasive effects of sand and wind: this again suggests the use of a 

harder stone. Soluble salt contamination is also less harmful to impervious stone, since 

the number of pores in which the salts can crystallise is limited. 

The thickness of the natural stone elements will depend on the type of fixing, the 

expected strength of the wind, the weight and density of the slabs, etc. For this reason, 

it is recommended to seek the advice of a professional. 

19

the effect of 

the surface finishing 


rough block of natural stone has little of the colour and 

A texture of the finished product (see the photograph of 

the block area on page 11). It is the finishing process which 

brings the true beauty of the stone to the surface and 

determines its final appearance. Polishing tends to make 

the colour darker and more intense. By contrast, flaming 

and other ‘rougher’ surface treatments tend to soften the 

colouring. 

There are eleven or so classic surface finishings (see 

You can find a detailed 

technical description 

of each finishing process 

on the inside front cover. 

The symbols in the list of 

natural stone types (page 

46 and following) also refer 

to the type of finishing. 

the examples alongside): from the much-used polishing 

technique to the less well-known frost flower patterning. 

Polishing can be used on a wide range of natural stone 

types: the main criteria are that the stone must be sufficiently 

compact and must contain enough ‘hard’ minerals. Granites 

and marbles are frequently polished, basalts and slates 

less so. 

A rougher finish can sometimes offer added aesthetic value 

and can sometimes be a matter of necessity. However, many 

marbles lose their vivid quality if given a rough finish. 


20


The influence of surface finishing on colour: 

polished 

bush-hammered 

ground Letano chiselled 

Anciento flamed sandblasted 

Rustenbuild ® 

frost flowers 

taille ancienne 

honed 

Before choosing the type of finishing you want, it is always advisable to 

seek the advice of a professional. They will know which fi nish can best be 

combined with the different types of natural stone. They will take account of the 

purpose for which you intend to use the stone (e.g. a rougher surface fi nishing 

for applications where an anti-slip function is important). 

21

three unique finishes: 

Anciento ,Calibrato and Letano 


With the Anciento process Brachot-Hermant has 

created its own unique finishing technique for 

granite. The same technique can also be used on a select 

group of marbles. 

The natural stone is first given a treatment which ‘roughens’ 

the surface, followed by a series of special abrasive 

brushes to ‘seal up’ and ‘finish off’ the stone. To assist 

the technique, the surface of the stone is mechanically 

impregnated during production, but a further impregnation 

is recommended following the final installation. 

The result? A stone with a ‘rough’ finish but a ‘soft’ feel. A 

stone with a beautiful satin sheen, which creates a unique 

natural atmosphere, both in and outdoors. A stone which is 

slip-free but easy to maintain. 

With the Calibrato process Brachot-Hermant hopes to 

supply an answer to the demand for light slabs and tiles. 

This sophisticated production process allows natural stone 

to be accurately calibrated to a thickness of as little as 

10 mm. Moreover, the slab – irrespective of its size – is the 

same thickness over its full surface area. This greatly 

facilitates the efficient laying of natural stone on support 

structures, such as braces. 


22


With the Letano process Brachot-Hermant has introduced yet another innovative 

technique for the finishing of granite. The light brushing helps to accentuate the 

natural colour of the stone, while the gloss fi nish gives a unique feel to the surface, 

equivalent to a ‘leather touch feeling’. Letano is ideal for use in a number of different 

applications: interior floors, bathrooms, cladding, kitchentops, etc. 

23

standards and tests 

for natural stone 


In Europe a distinction is made between three different 

types of standards: 

- standards relating to specific tests, such as porosity, 

compressive strength, hardness, etc.; 

- standards relating to classification and terminology, 

including the commercial names for European natural 

stones; 

- product standards, which set down the requirements 

which the natural stones must meet for use in particular 

applications (such as technical characteristics, tolerance 

levels for size and flatness, etc.). 

Until recently, many of the standards for the testing of 

natural stone were based on the standards for concrete. 

Fortunately, more and more standards are now being 

developed for the specific testing of natural stone. The 

following is an overview of the most important of these 

stone- specific standards. Should you require more detailed 

explanation, please feel free to contact the Brachot Stone 

Expert Centre. 

The Brachot 

Stone Expert Centre 

Know-how – both geological 

and technical – is of great 

importance in the natural 

stone sector. The Brachot 

Stone Expert Centre, 

headed by a doctor in 

geology, has compiled 

a detailed technical 

specifi cation sheet for each 

of the natural stones in the 

Brachot-Hermant range. 

These sheets can be 

obtained from your 

professional stone supplier 

or can be downloaded 

from our website 

www.brachot.com. 

The Brachot Stone Expert 

Centre will also be pleased 

to answer any technical 

questions you may have, 

relating to installation, use 

of adhesives, discoloration, 

etc. 


24

The 1 apparent volume mass (kg/m 3 ) 

European standard NBN EN 1936. 

This standard expresses the mass of the natural stone in kilograms per cubic metre (kg/m 3 ). 

This cubic metre is made up of stone and pores (air). 

The result gives an indication of the level of compactness of the natural stone. The higher the 

result, the more compact (and therefore less porous) the stone. 

limestone 1500 – 2800 kg/m 3 

marble 2600 – 2800 kg/m 3 

granite 2500 – 3000 kg/m 3 

slate 2650 – 3000 kg/m 3 

As might be expected, the granites and slates are far more compact than the limestones. 

In addition to the structure of the stone (open, closed, etc.), the composition of the constituent 

elements (minerals, etc.) also plays an important role in determining the volume mass. 

Porosity 2 (volume %) 


This standard indicates what percentage of the total volume (apparent volume) is made up 

by pores. 

A distinction is made between two different types of porosity: 

- closed porosity: the pores in the stone are separated from each other; 

- open porosity: the pore cavities are more or less linked by a series of chambers, allowing 

almost free passage to water. 

As a technical characteristic, professional stone dealers will sometimes quote an absorption 

level instead of a porosity level. This absorption level is expressed as a percentage of the 

mass (i.e., the mass of absorbed water in relation to the mass of the dry piece of tested 

stone). 

soft (white) limestone 5 to 50 % 

marble and compact limestone 0,2 to 5 % 

granite 0 to 2 % 

slate < 3 % 

25

There are large differences between the porosity levels for the various types of limestone. 

The percentage of pores gives a clear indication of the openness or density of the structure. 

These differences can be related to a number of factors, such as the depth of the strata from 

which the stone was extracted and the degree of metamorphosis which the stone underwent 

during its formation. Porosity levels will also often determine whether or not a stone can 

be polished – a finishing which is only suitable for stones of a suffi cient density. Account 

must also be taken of the fact that stone types which absorb water with diffi culty sometimes 

have problems in shedding this water at a later stage. This water retentiveness can be a 

disadvantage in terms of resistance to frost damage. 

Compressive 3 

strength (N/mm 2 ) 


This standard expresses the level of pressure/force which needs to be exerted to cause the 

stone to break. This level of pressure is expressed in Newtons per square millimetre (N/mm 2 ) 

and is adjusted to take account of the surface area of the stone being tested. 

This standard can be used to choose stone for particular building applications, where the 

materials will be exposed to specific load levels (taking account of the safety coeffi cient). 

In this respect, the heterogeneity of the stone plays an important role: some metamorphic 

stones have a grouping or alignment of their mineral elements in parallel lines or bands. 

This is known as foliation and the different layers have a clearly different mineralogical 

composition. This can result in widely differing compressive strengths, depending upon 

whether the pressure is applied perpendicular as parallel to the foliation. 

Indicative compressive strength levels are given in the table below. It should be noted that 

the levels vary widely, even within the same stone type. Yet again, the highest scores (in 

average terms) are recorded for granite. 

limestone 2 to 240 N/mm 2 

marble 40 to 230 N/mm 2 

granite 80 to 400 N/mm 2 

slate 40 to 260 N/mm 2 


26

Flexural 4 strength (tensile strength) (N/mm 2 ) 


The flexural strength – sometimes also referred to as the tensile strength – is expressed in 

Newtons per square millimetre and indicates the maximum pressure that a stone can bear for 

this specific type of load. The flexural strength is always much lower than the compressive 

strength (approximately 1/10 for granite/marble and 1/15 for sandstone). 

The bending capacity can be very important for certain natural stone applications, such as 

freestanding staircases or overhangs. It is also important to take account of bending capacity 

when there is a high risk of cracks forming, as a result of shrinkage and/or thermal stresses. 

Hardness 

5 

The hardness of a stone is usually indicated as a number which refers to the so-called MOHS 

table. This is a list of minerals, so ordered that a mineral can scratch the mineral before it in 

the table, but not the mineral after it. 

Natural stones are compositions of different types of minerals and the concentration of these 

minerals can vary widely from tile to tile, block to block, etc. The hardness of a particular 

natural stone is therefore determined by taking the average hardness of the minerals which it 

contains (but without taking account of the relative quantities of these minerals). This means 

that the hardness figure is not always fully accurate for every piece of stone of that type, but 

it does give a good indication of its susceptibility to scratching. The following are examples 

of stone hardness. 

- granite, gneiss: 6 to 7 (based on the presence of quartz and feldspar) 

- basalt, gabbro: 5 to 6.5 (based on the presence of feldspar and hornblende) 

- marble, limestone: 3 (based on the presence of calcite) 

This means, for example, that marble and limestone can be scratched by an ordinary kitchen 

knife, but that granite cannot. 

27

6 

Wear resistance (mm of mm/1000m) 

This is the ability of the stone to withstand wear and tear caused by abrasive movement. This 

measurement is especially useful for assessing whether or not a particular natural stone is 

suitable for use as a floor in a particular location. 

The wear resistance test examines the abrasive effect caused by the passage of people over 

a natural stone surface. This gives a more accurate indication than hardness of the suitability 

of the stone for use as a floor covering. 

A distinction is made between two different types of wear: 

- visible wear; 

- non-visible (or ‘deep’) wear. 

An example of visible wear is the fading of the sheen on polished stone (there are no 

standardised tests for this type of wear). It must be remembered that – irrespective of the 

basic hardness of the stone - there is always a risk that a polished surface will be worn away 

with use. The wear of polished surfaces is not only influenced by stone hardness, but also by 

a series of external factors, such as the intensity of use, maintenance and the presence of 

abrasive particles (grit, sand, dirt, etc.). 

As far as deep wear is concerned, there now exists a new European standard based on the 

so-called Capon test (NBN EN 14157). Prior to this, the Belgian Amsler test was widely used in 

Belgium (NBN B27-003). In practice, the relative newness of the Capon test (and consequent 

lack of data) means that the Amsler criteria are still frequently applied in Belgium. 

Wear 

resistance 

Intensive 

collective 

use 

Normal 

collective 

use 

Individual 

use 

Amsler 

(mm/1000m) 

≤ 4 ≤ 8 ≤ 12 

7 

Frost resistance 



28 

For this test pieces of natural stone are subjected to a repeated cycle of freezing and 

thawing. A measurement of the elasticity modulus determines whether or not the stone can 

be classified as frost-resistant.

Unfortunately, this European standard makes no comparison between the standard freezethaw 

test cycles and the actual conditions to which the natural stone will be subjected. In 

reality, every application of natural stone outdoors will experience differing levels of frost 

stress. For example, terrace tiles are normally in direct contact with a surface which can 

become frozen, whereas a ventilated cladding will undergo a much less severe frost regime. 

Various organisations are currently investigating whether or not alternative criteria, based on 

the European standards but more representative of actual conditions, can be devised. 

8 

Slip resistance 


This standard indicates the extent to which a natural stone limits the risk of slipping. 

The slip resistance of a tile has an effect on the comfort and safety of potential users, as 

well as on the cleanliness and general appearance of the floor. The level of resistance can 

diminish with time, as a result of wear, dirt, maintenance products, etc. 

The slip resistance value is to a large extent determined by the surface fi nishing of the tile. 

For applications where slip resistance is an important element, it is preferable to opt for a 

rougher finish. European criteria for this standard still need to be defi nitively established. 

Brachot-Hermant has invested heavily in know-how. 

The Brachot Stone Expert Centre is unique in 

Europe. Our technical data sheets are evidence of 

our thorough knowledge of the properties of natural 

stone. 

Each sheet contains detailed information relating 

to appearance, petrographic profile (if available), 

finishing options, technical specifications in 

respect of the above mentioned tests (if available), 

possible uses and recommended installation and 

maintenance techniques. 

29

Natural Art Collection 


Brachot-Hermant has searched in stone quarries 

across the globe to bring you the very finest products 

that nature can offer. Marbles, granites, onyx, quartz: each 

with its own unique structure and colouring. True pearls 

of nature, to which only a select group of experts have 

access. 

Blanc Sivec 

More than 30 exclusive types, which answer to such 

exotic names as Portoro, Azul Bahia, Onyx Verde, Breccia 

Oniciata... . Brachot-Hermant has brought together this 

exclusive collection in Stone Gallery in Deinze under the 

title of the Natural Art Collection. 

Breccia Oniciata 

Every slab of natural stone from this collection tells his 

own unique story. Unbelievable colour schemes, wonderful 

stuctures showing the dramatic creativity of the primal 

forces of mother earth: every slab is a true work of art, 

created by nature itself. 

If you require uniqueness and exclusivity, the stones in this 

collection are precisely what you are looking for. 

Crema Marfi l Select 


30

Calacatta 

Arabesco Vagli 

Vert Antigua 

Gaugin 

Marinace 

Lappia Green 

Comblanchien Claire Uni 

Portoro 

Marmo Nero Fossile 

31

Cremo Valencia 

Travertin Jaune 

Onyx Verde 

Travertin Rouge d’Iran 

Rosa Norvegia 

Juparana Florenza 

Rosso Verona 

Rouge de Languedoc 

Breccia Pernice 

Opera Fantastico 

Salome 

Rosso Bilbao 


32

Thassos White 

Penthelicon 

Azurro Argentino 

Azul Macaubas 

Palissandro Bluette 

Azul Bahia 

Blue Eyes 

Pietra Lavica 

Sodalite Blue 

33

the natural choice - Brachot-Hermant

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