EN 12407:2019

Natural stone test methods - Petrographic examination

This document specifies methods for making technical petrographic descriptions of natural stone, except for roofing slates. For this product, the method for the petrographic examination is defined in EN 12326-2. Although chemical and physical methods of analysis are required for petrographic classification of some stone types, these methods will not be described in this standard.

Prüfverfahren für Naturstein - Petrographische Prüfung

Dieses Dokument legt Verfahren für technische petrographische Beschreibungen von Naturstein, mit Aus-nahme von Dachschiefer, fest. Für dieses Produkt ist das Verfahren der petrographischen Untersuchung in EN 12326 2 festgelegt. Obwohl für die Klassifizierung einiger Gesteinsarten chemische und physikalische Analyseverfahren erforderlich sind, werden diese Verfahren in dieser Norm nicht beschrieben.

Méthodes d'essai de pierres naturelles - Examen pétrographique

La présente Norme européenne spécifie des méthodes permettant la réalisation de descriptions pétrographiques techniques des pierres naturelles, à l’exception des ardoises pour toitures. La méthode d’examen pétrographique de ce produit est définie dans l’EN 12326-2. Bien que la classification pétrographique de certains types de pierres requiert des méthodes d’analyse chimique et physique, ces méthodes ne sont pas décrites dans la présente norme.

Preskušanje naravnega kamna - Petrografska preiskava

Ta evropski standard določa metode za izdelovanje tehničnih petrografskih opisov naravnega kamna, razen za skrilavce za strehe. Za ta izdelek je metoda za petrografsko preiskavo opredeljena v standardu EN 12326-2. Čeprav so za petrografsko klasifikacijo nekaterih vrst kamna potrebne kemične in fizične metode analize, te analize niso opisane v tem standardu.

General Information

• Status: Published
• Publication Date: 04-Jun-2019
• Withdrawal Date: 30-Dec-2019
• ICS: 73.020 - Mining and quarrying
• ICS: 91.100.15 - Mineral materials and products
• Technical Committee: CEN/TC 246 - Natural stones
• Drafting Committee: CEN/TC 246/WG 1 - Terminology, classification and characteristics
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 30-Sep-2025
• Completion Date: 05-Nov-2025
• Ref Project: SIST EN 12407:2019 - Natural stone test methods - Petrographic examination

Relations

• Replaces: EN 12407:2007 - Natural stone test methods - Petrographic examination
• Effective Date: 08-Jun-2022

Overview - EN 12407:2019 (Natural stone test methods - Petrographic examination)

EN 12407:2019 is the CEN European Standard that specifies procedures for making technical petrographic descriptions of natural stone (excluding roofing slates). It defines the approach for macroscopic and microscopic examination, preparation of thin and polished sections, staining methods, and quantitative mineral modal analysis used to support petrographic classification and to relate petrographic features to technical behaviour.

Key topics and technical requirements

• Scope: Applies to natural stone (not roofing slates - see EN 12326-2). Chemical and physical analytical methods sometimes needed for classification are acknowledged but not described in this standard.
• Sample preparation:
  • Requirements for representative sample size and coherence; impregnation with resins for fragile stones.
  • Preparation of thin sections (≈ 0.03 mm thickness) and polished sections for opaque mineral study or microprobe work.
  • Typical section dimensions (e.g. 44 × 28 mm) and guidance for coarser grains or anisotropic textures (multiple orientations).
• Apparatus: Lists essential equipment - hand lens/stereoscope, water-cooled rock cutter, grinding/polishing machines, polarized transmitted light microscope, point counter or image analysis system, staining reagents.
• Macroscopic description: Colour (Rock Colour Chart recommended), structure (joints, bedding), grain size, pores/cracks, weathering, macrofossils, xenoliths.
• Microscopic description:
  • Fabric, mineral constituents, groundmass, discontinuities and alterations.
  • Quantitative modal analysis (volume % of mineral phases) by point counting or Shvetsov diagrams; Annex C gives point-counting principles.
  • Mineral characterization: volume percent, grain size ranges, habit, shape, boundaries, distribution, orientation, and alteration evidence.
• Staining procedures: Feldspar and carbonate staining (e.g., alizarin for distinguishing calcite/dolomite) are described (Annex B).
• Test reporting: Specifies content of the petrographic report and templates (Annex D).
• Normative references: EN 12440 (denomination criteria) and EN 12670 (terminology).

Practical applications and users

EN 12407:2019 is used to:

• Provide objective petrographic descriptions for stone classification, quality control and specification in the stone industry.
• Support material selection and durability assessment where petrographic features affect properties (e.g., porosity, water absorption, freeze–thaw susceptibility, mechanical strength).
• Aid architects, conservators and heritage professionals in provenance determination and restoration of historic monuments.
• Guide geologists, petrologists and testing laboratories preparing thin sections and producing standardized petrographic reports.
• Assist quarry operators and material suppliers in documenting product characteristics for clients and regulators.

Related standards

• EN 12326-2 - Roofing slates: petrographic examination method for slates
• EN 12440 - Natural stone: Denomination criteria
• EN 12670 - Natural stone: Terminology
• EN 16306 - (Referenced for marble thermal/moisture behaviour in specific contexts)

Keywords: EN 12407:2019, petrographic examination, natural stone test methods, thin section preparation, modal analysis, point counting, petrographic classification, CEN.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2019
Nadomešča:
SIST EN 12407:2007
Preskušanje naravnega kamna - Petrografska preiskava
Natural stone test methods - Petrographic examination
Prüfverfahren für Naturstein - Petrographische Prüfung
Méthodes d'essai pour pierres naturelles - Examen pétrographique
Ta slovenski standard je istoveten z: EN 12407:2019
ICS:
73.020 Rudarstvo in kamnolomsko Mining and quarrying
izkopavanje
91.100.15 Mineralni materiali in izdelki Mineral materials and
products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12407
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2019
EUROPÄISCHE NORM
ICS 73.020; 91.100.15 Supersedes EN 12407:2007
English Version
Natural stone test methods - Petrographic examination
Méthodes d'essai de pierres naturelles - Examen Prüfverfahren für Naturstein - Petrographische
pétrographique Prüfung
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, 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 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 12407:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols . 5
5 Principle . 5
6 Apparatus . 5
7 Preparation of thin and polished sections . 6
7.1 General . 6
7.2 Staining . 7
7.2.1 Feldspar staining . 7
7.2.2 Carbonate staining . 7
8 Macroscopic description . 7
9 Microscopic description . 7
9.1 General . 7
9.2 Fabric . 7
9.3 Constituents . 8
9.3.1 Minerals/Grains. 8
9.3.2 Groundmass. . 8
9.4 Discontinuities: . 8
9.5 Alterations: . 9
10 Petrographic classification . 9
11 Test report . 9
Annex A (informative) Preparation of thin sections . 11
Annex B (informative) Staining preparation and procedure of thin sections. 12
B.1 Staining preparation . 12
B.2 Staining procedure . 12
Annex C (informative) Principle and procedure of point counting. 14
Annex D (informative) Templates for the petrographic description of rocks . 15
Bibliography . 20

European foreword
This document (EN 12407:2019) 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 November 2019, and conflicting national standards
shall be withdrawn at the latest by November 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 12407:2007.
In comparison with the previous edition, the following changes have been made:
— the changes concern essentially the proper scientific definitions, terminology, and diagrams.
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.
Introduction
A petrographic description of natural stones is important not only for the purposes of petrographic
classification but also in order to highlight features affecting its chemical, physical and mechanical
behaviour. In the same way the determination of the stone’s origin could be necessary (e.g. in the case
of restoration of historical monuments). It is therefore essential to characterize the natural stones for
their mineral components and for their fabric and structure but also in terms of any features as: colour,
presence of veins, of fossils, of discontinuities, etc.
To ensure that the petrographic classification is objective, it is essential that the characterization of the
material is, as far as possible, quantitative.
The interpretation of the results obtained from the petrographic examination of natural stone should
include evidences of a possible relationship between petrographic features and technical properties
(pores/cleavages/schistosity with water absorption/gelivity/flexure resistance etc.).
1 Scope
This document specifies methods for making technical petrographic descriptions of natural stone,
except for roofing slates. For this product, the method for the petrographic examination is defined in
EN 12326-2. Although chemical and physical methods of analysis are required for petrographic
classification of some stone types, these methods will not be described in this standard.
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 12440, Natural stone - Denomination criteria
EN 12670, Natural stone - Terminology
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Symbols
vol.% unit of the volume percentage of the mineral phase present in the sample.
5 Principle
A macroscopic description of the sample is undertaken at first. The macroscopic description may
involve a visual inspection aided by a hand lens or a stereoscopic microscope. Then one or more thin
sections prepared from the sample are examined using an optical polarized transmitted light
microscope in order to give a microscopic description and modal analysis (volume proportions of
mineral phases) of the sample; where appropriate an additional polished section shall be prepared.
Modal analysis is the most accurate determination of quantitative mineralogical composition of natural
stones. It attributes to each mineral phase a certain percentage (vol.%). Modal analysis is obtained by
point counting following a standard procedure on thin sections (at least 44 mm × 28 mm) or using
Shvetsov’s diagrams (or any other similar diagrams commonly used by petrographers).
6 Apparatus
6.1 Hand lens or stereoscopic microscope (if required).
6.2 Water cooled rock cutter equipped with a continuous rim and sliding guide.
6.3 Automatic grinding machine or manual grinding machine with a cast-iron lapidary.
6.4 Electrical heating plate.
6.5 Bonding press.
6.6 Extractor hood.
6.7 Glass plate c. 300 mm × 400 mm × 10 mm.
6.8 Soft bristle brush.
6.9 Ultrasonic tank.
6.10 Polarized transmitted light optical microscope.
6.11 Point counter and image analysis system (if required).
6.12 Reactives and products as e.g.: emery with varying grain size (30 µm to 10 µm), epoxy resin,
Canada balsam, supporting glass (at least 28 mm x48 mm x1,8 mm), cover glass (24 mm x32 mm),
diamond disks, xylene and ethanol, amaranth, sodium cobaltinitrite, hydrofluoric acid, hydrochloric
acid, sulphosodic alizarin.
To facilitate the identification of some minerals with similar colours or optical properties it might be
necessary in many cases to use different techniques such as: selective mineral staining methods, optical
cathodoluminescence, XRD, SEM-EDS or WDS microprobe. If required, these methods should be clearly
stated in the working order referring to widely-referenced manuals, but taking into account that such
additional techniques are not part of the petrographic analysis described in this standard.
7 Preparation of thin and polished sections
7.1 General
Sampling is not responsibility of the test laboratory except where specially requested.
The dimensions of the sample shall be large enough to be representative of the petrographic
characteristics of the stone being examined.
One or more thin sections are then prepared.
A thin section is a portion of material mounted on a slide and mechanically reduced to a thin sheet
measuring 0,030 ± 0,005 mm in thickness, and normally protected by a slide cover. For special
purposes (observations under reflected light microscope for the determination of opaque minerals or
microprobe analysis) polished thin sections shall be prepared. Polished sections have one side polished
with a first polishing paste (in the range of ± 5 μm to 12 μm grade) and a second paste (in the range
of ± 6 μm, 3 μm and 1 μm).
The section normally measures about 44 mm × 28 mm, but in the case of coarser grain size stones,
larger dimensions may be used (e.g. 75 mm × 50 mm) or several sections of normal dimensions can be
prepared. If the rock texture is anisotropic it is necessary to prepare at least two sections with different
orientation with respect to the anisotropy (e.g. parallel and perpendicular to anisotropy planes).
Preparation of thick sections
The sample shall be sufficiently coherent so as not to disintegrate when cut. If the stone is brittle or
fragile, it will be necessary to strengthen it by means of impregnation, preferably in a vacuum, with
resins with an index of refraction approximately 1,54 (e.g. epoxy resins).
By using the rock saw, several small blocks are cut of dimensions in the range of at least ± 4-5 cm × ± 3-
4 cm and thickness in the range of ± 3 to 4 mm thick. In case of porous samples pores are filled with
Canada balsam (or any synthetic resin with approximately equivalent refractive index); the samples are
then heated on the plate to approximately 100 °C and then cooled.
Blocks are then successively ground using diamond discs between 1 and 2 min depending on the type
and hardness of their constituent minerals.
Preparation of thin sections
The detailed description of preparation of thin sections is given in Annex A (informative).
7.2 Staining
7.2.1 Feldspar staining
The detailed description of feldspar staining preparation and procedure is given in Annex B
(informative).
7.2.2 Carbonate staining
If samples are suspected of containing carbonates, their selective staining can be carried out. Samples
are etched with a HCl solution 1:20 and then immersed in a alizarine solution during 3 min. Then
samples are washed with water and are left to dry in open air. Calcite will then stain with a dark red
colour, dolomite will maintain its original colour and other carbonates will be stained between rose and
violet colour depending on the case. It is possible to discriminate other carbonates than calcite using
other chemical attacks, but this is not frequent.
8 Macroscopic description
Macroscopic description shall be carried out on fresh broken samples and, if considered necessary, on
polished samples.
The following observations shall be included in the macroscopic description:
a) The general colour or range of colours of the hand specimen. The colour can be estimated by visual
impression or defined using a colour reference chart (Rock Colour Chart is recommended).
b) Rock structure (joints, bedding, stylolites, etc).
c) Grain size (e.g. coarse, medium or fine).
d) Open and refilled macroscopic cracks, pores and cavities (when relevant).
e) Evidence of weathering and alteration: staining by sulphide alteration, diffusion of iron hydroxides,
alteration of feldspars etc. (when relevant).
f) Presence of macrofossils (when relevant).
g) Presence of xenolithic and/or autolithic inclusions (when relevant).
9 Microscopic description
9.1 General
The following observations shall be included in the microscopic description:
9.2 Fabric
As defined in EN 12670.
9.3 Constituents
9.3.1 Minerals/Grains
For the determination of the opaque minerals polished sections should be used.
For each mineral or grain identified, the characteristics listed below shall be specified (when relevant).
9.3.1.1 Percentage by volume (vol.%), specifying the method used (e.g. estimate, point counter).
The detailed principle and procedure are given in Annex C (informative).
9.3.1.2 Dimensions: mean value and range of variation (if necessary for the groundmass and also
for the larger crystals or grains). The range of sizes to be used will be: Very coarse (>10 mm), Coarse
(4 mm - 10 mm), Medium (1 mm - 4 mm), Fine (<1 mm). These values could not be used for clastic
rocks that require the widely-used Wentworth scale. In addition, the coarse-medium grain size limit for
igneous rocks is placed at 5 mm. Degree of sorting (in clastic rocks): very well sorted, well sorted,
moderately sorted, poorly sorted, very poorly sorted.
9.3.1.3 Habit (e.g. idiomorphic, anhedral).
9.3.1.4 Shape (e.g. isometric, anisometric, flattened, elongated). Detrital grains in sedimentary
rocks shall be described in terms of sphericity and roundness.
NOTE For marble see also EN 16306 Natural stone test methods — Determination of resistance of marble to
thermal and moisture cycles.
9.3.1.5 Boundaries (e.g. straight, lobate, dentate).
9.3.1.6 Distribution (e.g. homogeneous, heterogeneous, in layers, in patches).
9.3.1.7 Orientation (e.g. isotropic, shape preferred orientation, dimensional preferred orientation,
isorientation of lamellar or tabular grains, isorientation of elongated, prismatic grains).
9.3.1.8 Evidence of weathering and alteration: staining by sulphide alteration, diffusion of iron
hydroxides, chloritization of biotite; sericization of feldspars, radioactive decay of minerals such as
zircon or allanite etc.
9.3.2 Groundmass.
9.3.2.1 In volcanic rocks mesostasis which can be glassy, hypocrystalline, microcrystalline,
devitrified.
9.3.2.2 In sedimentary rocks have to be distinguished matrix (microcrystalline pelitic, carbonatic or
silicic mud which includes grains when present, or fills the interstices) and cement (amorphous to
crystalline materials partially or completely filling cavities).
9.3.3 Organogenic remains: e.g. organic or replaced (pyrite, apatite etc.) organogenic remains.
9.4 Discontinuities:
9.4.1 Pores, microcavities (size, shape, relative abundance and filling material if present).
9.4.2 Cracks and open fractures.
9.4.2.1 Width (most frequent value, minimum and maximum).
9.4.2.2 Length (most frequent value, minimum and maximum).
9.4.2.3 Type (intergranular, intragranular, transgranular)
9.4.2.4 Orientation.
9.4.2.5 Distribution.
9.4.3 Filled fractures and veins.
9.4.3.1 Width (most frequent value, minimum and maximum).
9.4.3.2 Length (most frequent value, minimum and maximum).
9.4.3.3 Type (intergr
...