MATERIALS HANDBOOK
Introduction
Rocks are classed into three classes according to their origins:
-
magmatic rocks
sedimentary rocks
metamorphic rocks
Magmatic rocks: originate from the solidification of the magma beneath the
earth’s crust. Magmatic rocks can be divided into:
- Intrusive or plutonic rocks formed from the solidification of the
magma deep below the surface (eg. granite, diorite ,sienite,
gabbro)
- Effusive or volcanic rocks formed from the solidification of the
magma on the earth’s surface (eg. basalt, porphry, trachyte)
- Pyroclastic rocks formed from the subaerial deposit of erupted
materials from volcanos like peperino.
MAGMATIC ROCKS
Basalt (Sicily)
Diorite (Piedmont)
Peperino (Latium)
Granite (Sardinia)
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Sedimentary rocks: originate from the deposition of preexisting rock debris
and/or animal or vegetal remains.
Sedimentary rocks are divided into:
-clast or mechanical deposited rocks formed from the stratification of
existing rock fragments which, by a process of cementing,
subsequently moulded together to form new coherent rocks such as
breccias, puddinghe and sandstones;
-physical-chemical deposited rocks such as travertine which is formed
in continental areas at the mouth of sources of limewater; following
the reduction in pressure and the dispersion of carbon dioxide
precipitation (deposition) of the calcium carbonate occurs;
-biochemical rocks formed from the deposit of the remains of animal
and vegetal organisms; the rocks of particular interest in this group for
ornamental use are limestones.
SEDIMENTARY ROCKS
Ceppo di Grè (Lombardy)
Arabescato Orobico grigio (Lombardy)
Pietra di Firenzuola (Tuscany)
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Metamorphic Rocks: formed from the chemical, physical and/or mechanical
transformation of magmatic or sedimentary rocks. Examples of metamorphic
rocks of magmatic origin are serizzi, serpentine schists and quartzites while
those of sedimentary origin are marbles.
METAMORPHIC ROCKS
Beola (Piedmont)
Bardiglio (Tuscany)
Slate (Liguria)
Pietra del Cardoso (Tuscany)
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Magmatic Rocks
solidification of melted masses
(magma)
Sedimentary Rocks
deposition of debris on the Earth
surface
Metamorphic Rocks
transformation of pre-existing rocks
(metamorphism)
The scientific and commercial classification of ornamental building
stones
Ornamental rocks can either be classified scientifically which essentially involves a definition
of their mineral composition or commercially which considers other criteria such as the
degree to which they can be worked and polished.
Commercial classification divides rocks into four main groups: granites, marbles, stones and
travertines.
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GRANITES: hard silicate rocks which can be
polished (granite, diorite, gabbro, sienite;
porphyry, andesite, gneiss, granulite)
According to EN standard 12670:2001 a granite
is a compact rock which can be polished and is
used for ornamental and building purposes. It is
composed mostly of minerals, such as quartz
and feldspar, the hardness of which on the
Mohs scale is between 5 and 7.
Commercially, other magmatic and volcanic
rocks with a porphyric structure and
metamorphic rocks with a similar composition to
granitoids such as gneiss are defined as
granites too.
Again, according to EN standard 12670:2001,
scienfically-speaking plutonic rocks containing
feldspar, quartz, small quanities of plagioclast,
mica and other minerals are also classed as
granites.
MARBLES: compact carbonatic rocks which
can be polished (marble, lime schist, compact
limestone).
These are compact rocks which can be
polished and used for ornamental and building
purposes.They are composed mostly of
minerals such as calcite, dolomite and
serpentinite, the hardness of which is between
3 and 4 on the Mohs scale. This category
includes rocks scientifically defined as marbles
as well as limestones, dolomites, limestone
brecce, travertines and serpentinites which can
be polished (EN 12670:2001).
Scientifically speaking EN 12670:2001 defines
marbles as metamorphic rocks with a carbonate
content of over 50% (calcite and dolomite)
formed from the metamorphic recrystallisation
of a carbonatic rock.
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STONES: compact or porous rocks which cannot
be polished (basalt, trachyte, conglomerate,
sandstone, clay, tufo, soft limestone, dolomite,
phyllite, micaschist, quartzite, serpentinite,
amphibolite).
Stones can be classified according to the
following groups:
-soft and/or compact rocks such as sedimentary
rocks (calcarenites, lime-cemented sandstones,
etc.) various pyroclastic rocks (peperino, tufo,
etc.)
-hard and/or compact rocks such as natural split
rocks (quartzites, micaschists, layered gneiss,
slates, etc.), some volcanites (basalts, trachytes,
leucites, etc..).
TRAVERTINES: are sedimentary rocks formed
from physical-chemical deposition on the earth’s
surface due to weathering from thermal mineral
waters with a strong concentration of calcium
carbonate. Calcium carbonate in the form of
calcite is the main component. Travertines have
a microcrystalline structure with pores; some
varieties cannot be polished.
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The technical characterisation of ornamental and building stones: new
standards and CE marking in the stone industry
Every rock has its own chemical, physical, mechanical and aesthetic characteristics
according to its origin and mineral and petrographic characteristics. Consequently, every
stone material has specific technical and ornamental propoerties which condition its
performance. It is therefore vital for designers to be aware not only of a material’s aesthetic
characteristics but also of its technical characteristics and in particular those which will
influence its performance for the specific use in question.
In addition, it is important for designers to be aware of current legislation on the subject of
stone products. The 89/106/CEE directive on construction products (CPD) deals with stone
materials with a view to removing the technical barriers which currently prevent the free
circulation of construction products in the EC markets.
The CPD applies to building materials and by this term means any product made to be
permanently incorporated in buildings and civil engineering works.
In Italy, the CPD has been applied with law 246/93 which sets out the criteria for placing
building materials on the market, based on the suitability of their use and the consequent CE
marking.
With regard to CE marking products bearing this mark comply with the criteria set out in the
89/100/CEE directive. Hence CE marking shows that the product complies with all the legal
requirements to be marketed in the European Economic Area.
However, this does not mean that the product is necessarily suitable for all the end uses in all
the Member States.
The tables below list the standards for natural stone products and the relevant references to
the different tests (geometric, petrographic, physical-mechanical, technological and durability)
which may be conducted on these materials. We have also provided some brief indications
as to the characteristics to be defined for each type of product.
Classification of the standards for natural stone products
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Standard product
1.1
Semi-finished products
1.1.1 Raw blocks (EN 1467)
1.1.2 Raw slabs (EN 1468)
1.2
Finished products
1.2.1 Slabs for cladding (EN 1469)
1.2.2 Slabs for floors and stairs (EN 12058)
1.2.3 Modular tiles (EN 12057)
1.2.4 Slabs for external paving (EN 1341)
1.2.5 Cubes for external paving (EN 1342)
1.2.6 Kerbs for pavements (EN 1343)
1.2.7 Products for discontinuous roofing (EN 12326-1)
1.2.8 Products for walls (prEN 771-6 rev*)
1.2.9 Solid products (in the process of being drawn up)
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Terms standards
EN 12440 Criteria for definitions
EN 12670 Terminology
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Test methods**
3.1
Geometric tests
EN 772-16 Determination of product sizes for walls
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EN 772-20 Determination of surface smoothness for wall products
EN 13373
Determination of geometric characteristics of products
3.2
Petrographic tests
EN 12407
Petrographic analysis
3.3
Physical-mechanical tests
EN 772-1
Determination of compressive strength for wall products
EN 772-11:2000/A1 Determination of water absorption coefficient by capillarity for wall products
EN 1925
Determination of water absorption coefficient by capillarity
EN 1926
Determination of compressive strength
EN 1936
Determination of real density and apparent density and of total and open porosity
EN 12372
Determination of flexural strength under concentrated load
EN 13161
Determination of flexural strength under constant movement
EN 13364
Determination of breaking load at dowel hole
EN 13755
Determination of water absorption at atmospheric pressure
EN 14146
Determination of dynamic elastic modulus by measuring the fundamental resonance
frequency
EN 14158
Determination of rupture energy
EN 14205
Determination of knoop hardness
EN 14579
Determination of sound speed propagation
EN 14580
Determination of static elastic modulus
EN 14581
Determination of thermal dilation coefficient
3.4
Durability tests
EN 12370
Determination of resistance to salt crystallisation
EN 12371
Determination of frost resistance
EN 13919
Determination of resistance to ageing by SO2 action in presence of humidity
EN 14066
Determination of thermal shock resistance
EN 14147
Determination of resistance to ageing by salt mist
3.5
Technological tests
EN 14157
Determination of the abrasive resistance
EN 14231
Determination of the slip resistance by means of the pendulum tester (friction)
* The ZA appendix to turn it into harmonised standard has been attached
** For slates for discontinuous roofing there is only one standard with all the test methods EN 12326-2
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Characteristics to be defined for individual product types
CHARACTERISTICS
Geometric characteristics
Definition of the geometric
characteristics of products EN
13373
Petrographic
characteristics
Petrographic examination
EN 12407
Physical-mechanical
characteristics
Raw
blocks
Raw slabs
Slabs for
claddings
Slabs for floors
and stairs
Modular
tiles
X
X
X
X
X
EN 1341
APP. A.
X
X
X
X
X
X
Raw
blocks
Raw slabs
Slabs for
claddings
Slabs for floors
and stairs
Modular
tiles
X(2)
X(2)
X(2)
Water absorption
coefficient by capillarity
Slabs for
Cubes for
external paving external paving
Kerbs for
pavements
Wall blocks
EN 1342
APP. A
EN 1343
APP. A
EN 772-16
EN 772-20
X
X
X
Kerbs for
pavements
Wall blocks
Slabs for
Cubes for
external paving external paving
EN 772 -11
EN 1925
Compressive strength EN
X
1926
Real density and apparent
density and of total and
open porosity EN 1936
Flexural strength under
concentrated load EN
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
EN 772 - 1
X
X
X
12372(1)
Flexural strength under
constant movement EN
13161
(1)
Breaking load at dowel
hole EN 13364
Water absorption at
atmospheric pressure EN
X
X(2)
X(2)
X(2)
X(2)
13755
Dynamic elastic modulus
by measuring the
fundamental resonance
frequency EN 14146
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Mechanical-physical
characteristics
Rupture energy EN 14158
Knoop hardness EN 14205
Raw
blocks
Raw slabs
Slabs for
claddings
Slabs for floors
and stairs
Modular
tiles
Slabs for
Cubes for
external paving external paving
Kerbs for
pavements
Wall blocks
Raw
blocks
Raw slabs
Slabs for
claddings
Slabs for floors
and stairs
Modular
tiles
Slabs for
Cubes for
external paving external paving
Kerbs for
pavements
Wall blocks
X
X
Sound speed propagation
EN 14579
Static elastic modulus EN
14580
Thermal dilation
coefficient EN 14581
Durability
Resistance to salt
crystallisation EN 12370
Frost resistance EN 12371
Resistance to ageing by
SO2 action in presence of
humidity EN 13919
Thermal shock resistance
EN 14066
Resistance to ageing by
salt mist EN 14147
Abrasive resistance EN
14157
Slip resistance by means of
the pendulum tester
(friction) EN 14231
(2)
(2)
(2)
X
X
X
X
X
X(2)
X(2)
X(2)
X(2)
X(2)
X(2)
X
X(3)
EN 1341 APP
C
EN 1342 APP
B
X
X(3)
EN 1341 APP
D
EN 1342 APP
C
(1) The two methods are alternatives
(2) Only upon request
(3) Only for use for floors and stairs
General notes
1) The test method to be applied for the various products is the one given in the first column, if not otherwise specified
2) For
the
test
methods
for
discontinuous
roofing
EN
12326
–
2
applies.
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For further information regarding CE marking in the stone industry and the requirements
for the current standards we advise you to consult the “Guida alla marcatura CE nel
settore lapideo” (Guide to EC marking in the stone industry) by the Internazionale Marmi e
Macchine Carrara Spa.
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