Natural stone - Terminology

This European Standard defines the recommended terminology covering scientific and technical terms, test methods, products, and the classification of Natural Stones. This standard does not cover roofing slate, for roofing slate see EN 12326-1 and EN 12326-2.

Naturstein - Terminologie

Diese Europäische Norm definiert die empfohlene Terminologie für wissenschaftliche und technische Begriffe, Prüfverfahren, Produkte und die Klassifizierung von Naturstein. Dachschiefer werden durch diese Norm nicht abgedeckt; für Dachschiefer siehe EN 12326-1 und EN 12326-2.

Pierre naturelle - Terminologie

La présente Norme européenne définit une terminologie recommandée des termes scientifiques et techniques, des méthodes d’essai et des produits ainsi qu’une classification des pierres naturelles. La présente norme ne couvre pas l'ardoise de toiture ; pour celle-ci, voir les EN 12326-1 et EN 12326-2.

Naravni kamen - Terminologija

Ta evropski standard opredeljuje priporočeno terminologijo, ki zajema znanstvene in tehnične izraze, preskusne metode, izdelke ter klasifikacijo naravnih kamnov. Ta standard ne zajema skrilavca za strehe, za slednjega glej standarda EN 12326-1 in EN 12326-2.

General Information

Status
Published
Publication Date
16-Jul-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-Jul-2019
Due Date
14-Sep-2019
Completion Date
17-Jul-2019

Relations

Effective Date
01-Sep-2019
Effective Date
08-Jun-2022

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SLOVENSKI STANDARD
SIST EN 12670:2019
01-september-2019
Nadomešča:
SIST EN 12670:2002
Naravni kamen - Terminologija
Natural stone - Terminology
Naturstein - Terminologie
Pierre naturelle - Terminologie
Ta slovenski standard je istoveten z: EN 12670:2019
ICS:
01.040.73 Rudarstvo in rudnine Mining and minerals
(Slovarji) (Vocabularies)
01.040.91 Gradbeni materiali in gradnja Construction materials and
(Slovarji) building (Vocabularies)
73.020 Rudarstvo in kamnolomsko Mining and quarrying
izkopavanje
91.100.15 Mineralni materiali in izdelki Mineral materials and
products
SIST EN 12670:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 12670:2019

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SIST EN 12670:2019


EN 12670
EUROPEAN STANDARD

NORME EUROPÉENNE

June 2019
EUROPÄISCHE NORM
ICS 01.040.91; 91.100.15 Supersedes EN 12670:2001
English Version

Natural stone - Terminology
Pierre naturelle - Terminologie Naturstein - Terminologie
This European Standard was approved by CEN on 15 April 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, North
Macedonia, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12670:2019 E
worldwide for CEN national Members.

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SIST EN 12670:2019
EN 12670:2019 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
3.1 Geological terms . 5
3.2 Quarrying terms . 58
3.3 Processing terms . 64
3.4 Products and installation terms . 73
4 Scientific classifications . 79
4.1 Geological time scale (informative) . 79
4.2 Scientific classification charts . 80
4.2.1 Igneous Rocks Classification Charts . 80
4.2.2 Sedimentary Rocks Classification Charts . 88
4.2.3 Most common specific names of metamorphic rocks (list modified after Fettes and
Desmons, 2007) . 94
Annex A (informative) Examples of petrographical families/groups used in building . 96
Annex B (informative) Alphabetical index . 100
Bibliography . 112

2

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SIST EN 12670:2019
EN 12670:2019 (E)
European foreword
This document (EN 12670:2019) has been prepared by Technical Committee CEN/TC 246 “Natural
stones”, the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2019, and conflicting national standards
shall be withdrawn at the latest by December 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12670:2001.
In comparison with the precious edition, the following changes have been made:
— the changes concern essentially the proper scientific definitions, terminology, and diagrams.
This document is one of a series of standards for natural stone products including denomination, test
methods and product standards.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
3

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SIST EN 12670:2019
EN 12670:2019 (E)
Introduction
The term Natural Stone groups several rock types with marked geological differences. The extraction,
elaboration and commerce of Natural Stone have set a very particular vocabulary. Many of these terms
have been taken from the popular or quarrymen language, which sometimes is far from scientific
definitions. This document establishes the terminological bases for geological and petrologic definitions
of Natural Stone and its classification. References to definitions of natural stone products, defined in
other European Standards, are provided when necessary. It also incorporates most of the popular or
commercial terminology.
The terminology covers the fields of geology, mining, processing, marketing and products of Natural
Stone. The included scientific classifications allow setting the scientific name of the stone varieties. If
the stone variety is not included in this document, the rock should be classified using its three main
mineralogical components.
4

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SIST EN 12670:2019
EN 12670:2019 (E)
1 Scope
This document defines the recommended terminology covering scientific and technical terms, test
methods, products, and the classification of Natural Stones. This document does not cover roofing slate,
for roofing slate see EN 12326-1 and EN 12326-2.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 12326-1, Slate and stone for discontinuous roofing and external cladding - Part 1: Specifications for
slate and carbonate slate
EN 12326-2, Slate and stone for discontinuous roofing and external cladding - Part 2: Methods of test for
slate and carbonate slate
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Geological terms
3.1.1
accessory minerals
rock forming minerals that occur in such small amounts that they are not relevant in the classification
or nomenclature of the rock
3.1.2
acid rock
igneous rock that contains more than 66 % vol. of silica
3.1.3
actinolite
Ca-Mg-Fe-amphibole (see amphibole formula)
3.1.4
agate
distinctly banded variety of chalcedony
3.1.5
age
fourth order geological time unit
Note 1 to entry: See Table 2.
5

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EN 12670:2019 (E)
3.1.6
agglomerate
pyroclastic rock in which bombs (with diameters greater than 64 mm) > 75 % vol.
3.1.7
agglutinate
welded splatter, commonly of basaltic composition, deposited ballistically in strombolian or fire
fountain volcanic eruptions
3.1.8
alabaster
fine grained, compact variety of gypsum, usually white or pale coloured and translucent
3.1.9
albite
sodium plagioclase, formula Na(AlSi O ) (see plagioclase)
3 8
3.1.10
alkali feldspar
alkali rich feldspars microcline, orthoclase, sanidine, albite, with less than 5 % vol. anorthite
Note 1 to entry: See feldspar and plagioclase.
3.1.11
allochems
coarser framework grains in most mechanically deposited limestones in the basin of sedimentation
Note 1 to entry: Allochems include: intraclasts, ooids, skeletal particles, pellets (including peloids).
3.1.12
allotriomorphic
anhedral
xenomorphic
mineral which shows in thin sections no characteristic or rational faces, suggested by its crystalline
structure
3.1.13
alteration
post-formational change of the mineralogical and or chemical composition of a rock brought about by
physical, chemical, or biological means, including actions of hydrothermal solutions and weathering
processes, excluding metasomatic and metamorphic changes
3.1.14
alumina
Al O
2 3
chemical compound used in fine polishing
3.1.15
amorphous
phase that does not have a crystalline structure
6

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SIST EN 12670:2019
EN 12670:2019 (E)
3.1.16
amphibole
family of dark ferromagnesian silicate minerals, general formula A B (Si,Al) O (OH) , where A = Mg,
2-3 5 8 22 2
2+ 2+ 3+
Fe , Ca, Na; B = Mg, Fe , Fe , Al
3.1.17
amphibolite
gneissose or granofelsic metamorphic rock mainly consisting of green, brown, or black amphibole and
plagioclase
Note 1 to entry: A gneissose/granofelsic mesostructure is typical of true amphibolites, in contrast with
schistose, green amphibole-albite greenschists.
3.1.18
amygdaloidal
texture of volcanic rocks where almond-shaped vesicles are, fully or partially, filled with secondary
minerals
3.1.19
analcime
mineral, Na(AlSi O )H O of the zeolite group
2 6 2
Note 1 to entry: See zeolite, secondary minerals.
3.1.20
andalusite
mineral, Al SiO polymorphous with sillimanite and kyanite
2 5
3.1.21
andesite
volcanic rock of intermediate composition mainly composed of plagioclase (oligoclase - andesine) and
one or more of the mafic minerals amphibole, pyroxene, and biotite
Note 1 to entry: See 4.2.1.5
3.1.22
anhedral
(see allotriomorphic, 3.1.12)
3.1.23
anhydrite
mineral with CaSO formula
4
3.1.24
anisotropy
vectorial behaviour of physical and mechanical properties in minerals and rocks, i.e. hardness in
kyanite, thermal expansion in calcite, flexural resistance in slate
3.1.25
ankerite
mineral of dolomite group with calcium and iron
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SIST EN 12670:2019
EN 12670:2019 (E)
3.1.26
anorthite
calcic plagioclase, Ca (Al Si O )
2 2 8
Note 1 to entry: See plagioclase.
3.1.27
anorthoclase
sodium-rich mineral of the alkali feldspar group, formula (Na,K)AlSi O
3 8
Note 1 to entry: Its composition, in terms of the mole fraction of the orthoclase component (or) and the albite
component (ab) is or ab to or ab (see feldspar, microcline, plagioclase, orthoclase).
40 60 10 90
3.1.28
anorthosite
plutonic rock mainly composed of anorthite – rich plagioclase and little or no mafic minerals
Note 1 to entry: See 4.2.1.2.
3.1.29
antiperthite
perthitic intergrowth of plagioclase host and subsidiary K-rich feldspar
3.1.30
apatite
group of minerals, of which the formula is Ca (PO ,CO ) (F,OH,Cl)
5 4 3 3
3.1.31
aphanitic
of or relating to an igneous rock in which the crystals are so fine that individual minerals cannot be
distinguished with the naked eye
Note 1 to entry: Aphanitic rocks are extrusive rocks that cooled so quickly that crystal growth was inhibited.
3.1.32
aplite
fine grained igneous rock of granitic composition with allotriomorphic texture and, commonly,
leucogranitic composition
3.1.33
aragonite
mineral, polymorphous with calcite, of which the formula is CaCO
3
3.1.34
Archaean
the older eon of the Precambrian ranging from the formation of the Earth at ~4 000 Ma to 2 500 Ma
Note 1 to entry: See Table 1.
3.1.35
arenite
loose soil or consolidated sedimentary rock, mainly composed of sand size detrital lithic fragments or
mineral grains (between 1/16 mm and 2 mm)
Note 1 to entry: Usually the term is used with a prefix that refers to its composition or genesis, e.g.
quartzarenite (see 4.2.2.5).
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EN 12670:2019 (E)
3.1.36
argillite
layered or not-layered consolidated sedimentary rock mainly composed of detrital clay size particles or
clay minerals
3.1.37
arkose
sedimentary detrital rock with less than 75 % vol. quartz and a high content of feldspar grains
Note 1 to entry: See 4.2.2.5.
3.1.38
arkosic wacke
sandstone comprising >5 % vol. of sand grade particles, with the feldspar content exceeding that of rock
fragments and >15 % vol. of mud matrix (material <30 µm in diameter)
3.1.39
ash
fine-grained volcanic material
3.1.40
augen fabric
fabric in some rocks, usually metamorphic, consisting of ellipsoidal or lens shaped porphyroblasts,
crystals, or fragments, rounded and enveloped by the foliation, resembling eyes (augen) in a cross
section
3.1.41
augen mylonite
mylonite containing distinctive large crystals or lithic fragments around which the foliated fine-grained
matrix is wrapped, often forming symmetric or asymmetric trails
3.1.42
augite
clinopyroxene
mineral of the pyroxene group (clinopyroxenes), the general formula of which is
2+ 3+
(Ca,Na)(Mg,Fe ,Al)(Si,Al) O with minor amounts of Na, Fe , Al, Ti admitted, the colour of which is dark
2 6
green to black, and which is an essential constituent in basic igneous rocks such as basalts and gabbros
3.1.43
bafflestone
autochthonous carbonate rock whose original components were bound organically during deposition,
the organisms forming baffles to trap finer matrix material
3.1.44
banded
rock having alternating nearly parallel layers that differ in colour, fabric or mineral composition, and
because of that it shows alternating bands in a cross section
3.1.45
basalt
volcanic rock consisting essentially of plagioclase (labradorite-bytownite) and pyroxene with variable
amount of phenocrysts set in a fine-grained matrix
Note 1 to entry: Commercially natural stone as per the scientific definition of basalt and other rocks such as,
picrites, diabases, dolerites and microgabbros.
Note 2 to entry: See 4.2.1.5.
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EN 12670:2019 (E)
3.1.46
basanite
silica-undersaturated alkali olivine basalt containing olivine, clinopyroxene and plagioclase feldspar
with >10 % vol. feldspathoids in the form of nepheline or leucite, which is found in association with
other alkaline igneous rocks
3.1.47
basic
Mg,- Fe- and Ca-rich igneous rock with more than 45 % vol. and less than 52 % vol. of silica
3.1.48
bed of blocks
unweathered rock beneath unconsolidated material formed by blocks
3.1.49
bedding plane
a) planar or nearly planar surface that visibly separates the individual beds, layers or strata, in
sedimentary rocks;
b) any surface, even when conspicuously bent or deformed by folding
3.1.50
benmoreite
alkali lava intermediate in composition between mugearite and trachyte
3.1.51
bindstone
autochthonous carbonate rock whose original components were bound organically during deposition,
with the organisms binding finer matrix material together
3.1.52
bioclastic rock
sedimentary rock consisting of fragments and broken remains of organisms; e.g. limestone composed of
shell fragments
3.1.53
biolithite
limestone essentially constituted of reef structures, animal or plant
3.1.54
biotite
2+ 3+
mafic rock forming mineral of the mica group with general formula K(Mg,Fe ) (Al,Fe ) Si O (OH)
3 3 10 2
3.1.55
black granite
commercial term for black or dark coloured plutonic rocks
Note 1 to entry: See e.g. gabbro, diabase, basalt.
3.1.56
blasto-
prefix used to describe the metamorphic rock fabrics denoting the presence of primary crystals or pre-
existing fabric modified by metamorphism, but still recognized; e.g. blastogranular, blastomylonitic,
blastopsephitic
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EN 12670:2019 (E)
3.1.57
blastomylonite
mylonite which displays a significant degree of grain growth related to or following deformation
3.1.58
block
angular fragment of rock with a diameter >256 mm
3.1.59
blue schist
schist whose bluish colour is due to the presence of sodic amphibole
3.1.60
bomb
mass of liquid lava thrown through the air which rotates and takes on a characteristic shape and
structure
3.1.61
boundstone
limestone, in which the grain were bound by an organism or organisms
3.1.62
breccia
a) coarse grained clastic sedimentary rock composed by angular rock fragments held together by a
mineral cement or in a fine grained matrix;
b) clastic rock consisting of highly angular gravel-size fragments, of sedimentary, tectonic or volcanic
origin
3.1.63
calc silicate marble
marble with calcium and silicate minerals
Note 1 to entry: See marble, ophicalcite.
3.1.64
calcarenite
limestone consisting predominantly of recycled detrital calcite grains of sand size (1/16 mm – 2 mm)
3.1.65
calcareous
containing calcium carbonate
3.1.66
calcilutite
limestone consisting predominantly of detrital calcite grains or fragments of silt or clay size (<1/16
mm)
3.1.67
calciphyre
metacarbonate rock containing a conspicuous amount of calcium- and/or magnesium-silicate minerals
11

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SIST EN 12670:2019
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3.1.68
calcirudite
limestone consisting predominantly of detrital calcite grains or fragments larger than sand size
Note 1 to entry: See rudite.
3.1.69
calcisiltite
limestone consisting predominantly of detrital calcite grains or fragments of silt size
3.1.70
calcite
mineral, the formula of which is CaCO ; trimorphous with aragonite and vaterite
3
Note 1 to entry: Very common in some sedimentary and metamorphic rocks.
3.1.71
calcitic dolomite
carbonate rock which 50 % vol. to 89 % vol. of the mineral dolomite
Note 1 to entry: See also 4.2.2.11.
3.1.72
calcitic marble
marble containing more than 50 % vol. of calcite
3.1.73
calc-schist
carbonate silicate-schist
metamorphosed argillaceous limestone containing calcite as a substantial component and with a
schistose structure produced by parallelism of platy minerals
Note 1 to entry: The term carbonate-silicate schist should be used when the non-carbonate mineral content is
>50 % vol. See schist, 4.2.3.
3.1.74
Cambrian
oldest system and period into which the Palaeozoic is divided
Note 1 to entry: See Table 1.
3.1.75
carbonate
2-
mineral containing CO ; calcite, dolomite, magnesite, and siderite, etc. which are frequent rock forming
3
carbonate minerals
3.1.76
carbonate rock
rock consisting chiefly of carbonate minerals, especially a sedimentary rock; limestone, dolomite, and
carbonatite are examples of carbonate rocks
Note 1 to entry: See 4.2.2.8, 4.2.2.9, 4.2.2.10 and 4.2.2.11.
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EN 12670:2019 (E)
3.1.77
carbonate-silicate rock
metamorphic rock mainly composed of silicate minerals (including calcium-silicate minerals) and
containing between 5 % vol. vol and 50 % vol. vol of carbonate minerals
3.1.78
Carboniferous
period and system of the Palaeozoic
Note 1 to entry: See Table 1.
3.1.79
cataclasite
fault rock which is cohesive with a poorly developed or absent schistosity, or which is incohesive,
characterised by generally angular porphyroclasts and lithic fragments in a finer-grained matrix of
similar composition
Note 1 to entry: Generally, no preferred orientation of grains of individual fragments is present as a result of the
deformation, but fractures may have a preferred orientation. A foliation is not generated unless the fragments are
drawn out or new minerals grow during the deformation. Plastic deformation may be present but is always
subordinate to some combination of fracturing, rotation and frictional sliding of particles. Cataclasite may be
subdivided according to the relative proportion of finer-grained matrix into protocataclasite, mesocataclasite and
ultracataclasite
3.1.80
cataclastic
pertaining to the structure and texture produced in a rock by severe mechanical stress during dynamic
metamorphism; bending, breaking, and fragmentation of the mineral grains are characteristic features;
also said of the rocks exhibiting such structure
Note 1 to entry: See breccia.
3.1.81
cement
mineral material, usually chemically precipitated during the rock compaction that occurs in the
interstitial spaces among the individual grains of a sedimentary rock, thereby binding the grains
together as a rigid mass; silica, carbonates and iron oxides are common cements
3.1.82
Cenozoic
youngest era of geologic time
Note 1 to entry: See Table 1.
3.1.83
chalcedony
group name for the compact varieties of silica composed of minute crystals of quartz with sub
microscopic pores
3.1.84
chalcopyrite
sulphide mineral, the formula of which is CuFeS2
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EN 12670:2019 (E)
3.1.85
chalk
soft fine grained limestone, usually white consisting mostly of calcitic remains from microorganisms,
and minor silt and clay
3.1.86
charnockite
orthopyroxene-bearing rock of granitoid composition
3.1.87
chert
fine-grained, hard, compact and dense sedimentary rock, consisting dominantly of the SiO minerals
2
quartz, chalcedony and opal. cryptocrystalline and/or amorphous silica
Note 1 to entry: Flint is a variety of chert.
3.1.88
chlorite Group
2+ 3+
group of phyllosilicates, some of them of green colour, with general formula (Mg, Fe , Fe )
6
AlSi O (OH)
3 10 8
3.1.89
chloritoid
micaceous mineral, the formula of which is Fe Al Si O (OH)
2 4 2 10 4
3.1.90
chromite
mineral, the formula of which is (Fe,Mg)(Cr,Al) O
2 4
3.1.91
chronostratigraphic unit
stage or zone which, independent of facies, represents a layer of specific age
3.1.92
cipollino marble
impure marble with band coloured structure, consisting in layers of calcite or dolomite grains mixed
with variable quantities of silicate minerals
3.1.93
clast
mineral or rock fragment composing clastic sedimentary rocks
3.1.94
cisuralian
oldest epoch of the Permian
Note 1 to entry: See Table 1.
3.1.95
clastic
pertaining to a rock or sediment composed principally of broken fragments that are derived from pre-
existing minerals, rocks or organic structures and that have been transported some distance from its
original place
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EN 12670:2019 (E)
3.1.96
clay minerals
group of minerals, essentially hydrous silicates of aluminium with a layered crystalline structure; iron,
magnesium, potassium, and other cations are also present in their formula; the most common of which
belong to illite, montmorillonite, and kaolinite mineral subgroups
3.1.97
clay slate
shale
weakly metamorphosed clay stone with intermediate character between a clay stone and a true slate
3.1.98
clay
loose, extremely fine grained sediment or soft rock composed of particles with diameters less than
0,002 mm, mainly of clay minerals and other minerals, especially quartz, feldspars, and carbonates
3.1.99
clay stone
rock with more than 67 % vol. clay sized minerals
3.1.100
cleavage
a) property of a rock to split along closely spaced planar surfaces (see slaty cleavage, crenulation
cleavage, schistosity, and rough cleavage);
b) splitting of a mineral along its crystallographic planes, thus reflecting crystal structure
3.1.101
clinopyroxene
monoclinic pyroxene exhibiting non-parallel extinction
3.1.102
columnar
structure of some volcanic rocks, such as basalt, consisting of parallel, prismatic columns, polygonal in
cross section, nearly perpendicular to the top and the bottom of the flow unit
3.1.103
comb layering
fabric of igneous rocks consisting of bands of elongated crystals with nearly vertical mineral-elongation
relative to the border of the bands
3.1.104
concretion
collective term applied loosely to various primary and secondary segregations of diverse origin,
including irregular nodules, spherulites, crystalline aggregates, geodes, septarias and related bodies
3.1.105
conglomerate
coarse grained sedimentary rock composed of rounded to sub angular fragments (pebbles, cobbles,
boulders), set in a fine grained matrix of sand or clay, and commonly cemented
3.1.106
consertal
fabric of rocks showing toothed border lines between adjoining crystals
15

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EN 12670:2019 (E)
3.1.107
contact (between grains)
mode of relation between grains of rock-forming minerals; i.e. by points, by lines, within the matrix
3.1.108
coral rock
coral reef limestone
3.1.109
cordierite
silicate mineral, common in some metamorphic and rare in magmatic rocks, the formula of which is
(Mg,Fe) Al Si O
2 4 5 18
3.1.110
corona
fabric of igneous or metamorphic rocks where minerals are surrounded by a seam of one or more other
minerals
Note 1 to entry: Particular examples are the rapakivi fabric and kelyphitic rims.
3.1.111
Cretaceous
youngest of the periods/ and systems included in the Mesozoic era/erathem
Note 1 to entry: See Table 1.
3.1.112
cross bedding
cross stratification with thick individual beds
3.1.113
crossed twinning
lamellae of mineral twins after two laws making in thin sections a grid as seen in microcline
3.1.114
cryptocrystalline
composed of crystals so fine that they cannot be recognized even under polarizing microscope
3.1.115
crystal zoning
texture of igneous crystals with concentric layers made by inclusions or variations in chemical
composition e.g. in plagioclases
3.1.116
dacite
volcanic rock with quartz, plagioclase, alkali feldspar, and often mafic components
Note 1 to entry: See 4.2.1.5.
3.1.117
dark mineral
mafic mineral
Fe-Mg rock forming minerals, e.g. olivine, pyroxenes, amphiboles and biotite
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SIST EN 12670:2019
EN 12670:2019 (E)
3.1.118
decussate
metamorphic fabric of randomly oriented unequidimensional grains (e.g. pyroxenes, micas)
3.1.119
dedolomitization
partial or complete calcification of dolomite
3.1.120
deformation fabric
tectonic fabric
rock fabric resulting from deformation, as lineation, cleavages, schistosity, folds, preferred orientations
of crystals etc.
Note 1 to entry: See fabric.
3.1.121
devitrification
process of nucleation and growth of crystals in glasses at sub solidus temperatures
3.1.122
Devonian
system of the Palaeozoic Erathem above the Silurian and below the Carboniferous
Note 1 to entry: See Table 1.
3.1.123
diabase
medium grained rock of basaltic composition used in two ways: altered basaltic rocks (British) and
ophitic texture (French, German and American)
3.1.124
diagenesis
process of mineralogical changes in sediments after deposition which result in a consolidated rock
3.1.125
diamictite
terrigenous sedimentary rock with particle sizes
...

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