🏗️ Identification of the petrographic type of natural aggregates and rocks in a simplified description — examination with the naked eye, a hand lens and a stereoscopic microscope (10–100×), optionally a polarizing microscope, a magnet and dilute hydrochloric acid; description of grain size, texture, porosity, colour, main minerals and weathering; for aggregates — shape, surface and roundness of particles 0,1–63 mm (fine ones below 4 mm under the stereomicroscope) and a name according to the predominant type or mineral (> 50 %) or “heterogeneous”; natural aggregates only, PN-EN 932-3

Construction PN-EN 932-3

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 932-3:2022-12 (English version; scope in Polish on the card), in full (our translation of the Polish card text): “This document specifies a simplified procedure for identifying the petrographic type of natural aggregates. It concerns the usual requirements for the procedure and terminology of simplified petrographic description. Precise petrographic identification, for the purposes of technical mineralogy and petrography in civil and environmental engineering or for a specific end use, requires further examination and is therefore excluded from the scope of this document. NOTE 1 A qualified geologist (petrographer), with experience of materials used in civil and environmental engineering and aware of the components of the deposit, has sufficient skills to examine and describe the rock. NOTE 2 For precise petrographic identification and technical requirements for specific applications, a non-exhaustive list of reference literature is given in the Bibliography. This document applies only to natural aggregates. It is not used for the description and identification of manufactured or recycled aggregates. Annex A contains guidance on petrographic nomenclature, giving definitions of basic petrographic terms applicable to rock types used for aggregates.” We read the text of the standard in the preview of SIST EN 932-3:2022 (text of EN 932-3:2022) from the cover to clause 7.2 c) (page 9); we do not have the further optional report data or Annex A with the nomenclature.

ACCORDING TO THE TEXT OF EN 932-3:2022 (foreword, Clauses 1–7.2 c). The standard was prepared by CEN/TC 154 “Aggregates” (secretariat BSI); CEN approved it on 20 April 2022; it supersedes EN 932-3:1996. Technical changes: a) the scope emphasizes that the method applies only to simplified (not precise) petrographic description of natural aggregates and not to manufactured or recycled aggregates; the term “petrographic type” (as in product standards) is used throughout; Note 1 was reworded to show the role of the petrographer without normative wording; presentation of Annex A added; b) foreword and references updated; c) Clauses 3 (terms) and 4 (reagent and apparatus) extended; d) Clauses 5–7 restructured into 5 “Sampling and preparation of test portion” and 6 “Test procedure” (examination, description, designation); e) test report revised; f) Annex A updated and extended with three figures; g) bibliography extended. Other parts of EN 932: 1 — sampling, 2 — reducing laboratory samples, 5 — common equipment and calibration, 6 — repeatability and reproducibility. Scope (Clause 1, as on the card): basic procedure for identifying the petrographic type of natural aggregates, to describe rocks and sediments. References: EN 932-1, EN 932-2, EN 933-2 (sieves). Definitions (Clause 3): rock — natural solid substance of crystals or minerals (also natural glasses), igneous, sedimentary or metamorphic; igneous rock — crystallized from magma at or below the surface (plutonic — in large bodies at depth, usually coarse-grained; hypabyssal — in smaller bodies near the surface, usually fine-grained; extrusive — lavas and pyroclastics with very fine or glassy texture); sedimentary — formed from sediments by diagenesis and lithification, usually stratified; metamorphic — transformed by fluids or heat (contact metamorphism) and pressure (burial), often with an anisotropic texture; sediment — unconsolidated fragments of rocks or minerals (clastic, e.g. sand, gravel; chemical, e.g. kaolin; biogenic); laboratory sample; test portion. Reagent and apparatus (Clause 4): sieves according to EN 933-2, at least the 4 mm sieve; hand lens; pen knife; stereoscopic microscope with a magnification of usually 10–100×; polarizing microscope (optional); dilute hydrochloric acid (note: limestone usually reacts with acid of about 10 %, dolomite with about 20 %); magnet (optional). Sampling (Clause 5): the laboratory sample is taken from exposed faces of exploitation sites, drill cores or aggregate stockpiles (aggregates — according to EN 932-1); rock — test portion of at least 5 kg; aggregate — the minimum mass of the sample depends on the size D and the petrographic heterogeneity, reduction according to EN 932-2, representative portion; note: for a heterogeneous aggregate (no type or mineral predominant) 150 particles are usually sufficient. Description of a rock (6.1): first a visual examination to establish the constituents (the sample may be washed), then each rock type carefully with a hand lens or stereomicroscope; the description includes a) grain size of the main constituents, texture, anisotropy, porosity, vesicularity (volcanic rocks) and colour, b) identifiable main minerals (quartz, feldspars, calcite, dolomite etc.), c) state of alteration and weathering; note 2: the description may indicate the presence, even in small quantities, of constituents of concern in particular circumstances (opal, micas and other phyllosilicates, sulphates, iron sulphides and other sulphides, organic materials); rock name (6.1.2) — if possible, according to the nomenclature of Annex A. Description of an aggregate (6.2): aggregates from natural deposits consist mainly of mineral particles and rock fragments; examination, description and designation apply only to particles from 0,1 mm to 63 mm (the portion may be washed; composition often varies between fractions — they must then be separated and proportions estimated by counting particles in the fractions); particles retained on the 4 mm sieve may be examined with the naked eye, preferably with a hand lens or stereomicroscope, finer ones — obligatorily with the stereomicroscope; note: in some cases other methods — magnet, acid test for calcite, X-ray diffraction, thin sections under a polarizing microscope (preparation according to EN 12407); the description includes a) shape, surface condition (roughness) and roundness of particles, b) identification of the main minerals; designation (6.2.3): the petrographic type or mineral predominant (more than 50 %) must appear in the name — e.g. quartzose sand (more than 50 % quartz grains), basaltic gravel (more than 50 % basalt fragments); sand and gravel in the geological sense (A.3.2.1, A.3.2.2), not the geometric one; when nothing predominates — the material is “heterogeneous”, and the name should include the most frequent types (e.g. quartzo-feldspathic sand, siliceous gravel); for individual particles: petrographic type, minerals (e.g. quartz, feldspars, micas, calcite), shell fragments. Test report (7.1): reference to the standard with year of publication, identification of the sample with origin, identification of the laboratory, date, petrographic description according to 6.1 (rocks) or 6.2 (aggregates), deviations from the method, unusual observations; optional data (7.2): sampling procedure, reduction procedure, mass of the rock sample or portion…; this is where the part we read ends.

STATUS (cards as of 02.10.2026). The card of PN-EN 932-3:2022-12 (English version, published 01-12-2022, 20 pages, price group K) has no “Withdrawn” header: Construction and Building Structures Sector, KT 108 Aggregates and Building Stone, ICS 91.100.15, “Introduces: EN 932-3:2022 [IDT]”, “Replaces: PN-EN 932-3:1999 – Polish version, PN-EN 932-3:1999/A1:2004 – Polish version”. PN-EN 932-3:1999 (Polish version, published 07-01-1999, 12 pages; introduced EN 932-3:1996, replaced PN-B-06714-11:1987) and amendment PN-EN 932-3:1999/A1:2004 (Polish version, 08-12-2004; Scope: “A provision is given, for heterogeneous aggregates, on assessing a minimum number of 150 particles. Modifications concerning normative references and cross-references were introduced”, our translation) — both with “Withdrawal date: 01-12-2022”, replaced by PN-EN 932-3:2022-12.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read on 02.10.2026). The number 932-3 appears in 8 records at 7 laboratories: AB 054, AB 298, AB 687, AB 937, AB 1107, AB 1685, AB 1959. In the current scopes on the PCA website (read on 02.10.2026, issues from 07.10.2025 to 01.07.2026) the number appears at all 7: “PN-EN 932-3:2022-12” at AB 298, AB 687, AB 1107, AB 1685 and AB 1959; without the year at AB 054 and AB 937 (two places in the scope). No row with this number is set in bold italics (at AB 054 the suspension at the request of the body from 25.06.2026 concerns another part of the scope). The “Laboratories” tab searches for entries BEGINNING WITH “PN-EN 932-3” and shows all 7 laboratories — checked with a query of the tab on the production server labcoda.pl on 02.10.2026.

WHAT THE LABORATORIES TEST (items in the PCA scopes). Aggregates (AB 1685 — aggregates and rocks) — “simplified petrographic description”, at AB 687 and AB 1959 by the macroscopic assessment method, at AB 1685 “petrographic description — macroscopic and microscopic assessment”; usually next to other aggregate tests: freeze-thaw resistance (PN-EN 1367-1, -6), sonnenbrand of basalt (PN-EN 1367-3), particle length (PN-EN 13450), humus and sulphur content (PN-EN 1744-1), alkali reactivity (GDDKiA procedure) and sampling (PN-EN 932-1).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Scope: this is a SIMPLIFIED description — precise identification (technical mineralogy, specific applications) requires further examination, and manufactured and recycled aggregates are not covered by this standard. Fractions: composition often varies between fractions — a description of the whole sample without separating fractions may misjudge proportions; description and designation apply only to particles of 0,1–63 mm. Magnification: particles below 4 mm are assessed obligatorily under the stereomicroscope, not with the naked eye. Name: a type or mineral must exceed 50 % to appear in the name; otherwise the aggregate is “heterogeneous”, and “sand” and “gravel” are understood geologically, not by grading. Number of particles: for a heterogeneous aggregate usually 150 particles; a rock sample at least 5 kg. Acid: limestone already reacts with about 10 % HCl, dolomite — with about 20 %. Harmful constituents: opal, micas, sulphates, sulphides and organic materials should be indicated even in small quantities. Edition: the 2022 edition restructured the procedure and the report — results according to PN-EN 932-3:1999 (withdrawn) have a different arrangement.

WHAT WE DO NOT GIVE. We do not have Annex A (rock nomenclature with figures) or the remaining optional report data — so we do not give definitions of individual rock names or the full list of optional data.

Method principle

A petrographer examines a rock sample or aggregate portion with the naked eye, a hand lens and a stereoscopic microscope (aided by hydrochloric acid, a magnet, possibly thin sections), describes grain size, texture, minerals and weathering or shape and roundness of particles, and assigns a name according to the predominant type or mineral (more than 50 %) or describes the aggregate as heterogeneous.

Applications

• Natural aggregates — simplified petrographic description and name of the petrographic type — 7 laboratories in the PCA scopes
• Rocks in deposits and drill cores (sample of at least 5 kg)
• Indication in the description of constituents that may be harmful in particular circumstances (opal, sulphides, sulphates, organic materials)

Key parameters

Standard

Standard number

PN-EN 932-3:2022-12 (wersja angielska; EN 932-3:2022 IDT)

Title (PL)

Badania podstawowych właściwości kruszyw — Część 3: Procedura i terminologia uproszczonego opisu petrograficznego

Title (EN)

Tests for general properties of aggregates — Part 3: Procedure and terminology for simplified petrographic description

Step-by-step procedure

1. Sampling and preparation

   Rock from faces of workings or cores (≥ 5 kg); aggregate according to EN 932-1, reduced according to EN 932-2. PN-EN 932-3:2022-12 current (cards as of 02.10.2026).

2. Preparation of aggregate

   Possible washing and separation into fractions; examination only of particles 0,1–63 mm.

3. Examination

   With the naked eye, a hand lens and a stereomicroscope (particles < 4 mm obligatorily with the stereomicroscope); if necessary hydrochloric acid, magnet, thin sections.

4. Description

   Rock: grain size, texture, anisotropy, porosity, colour, minerals, weathering; aggregate: shape, surface, roundness, minerals; proportions from counting particles in fractions.

5. Name and report

   Name according to the type or mineral > 50 % (rocks — according to Annex A) or “heterogeneous”; report according to 7.1.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The part of the standard we read contains no safety warnings; hydrochloric acid — gloves and goggles, work in a fume cupboard; pen knife — care
• TECHNICAL NOTE: the standard gives a simplified description only for natural aggregates; the name requires predominance above 50 %, and particles below 4 mm are assessed under the stereomicroscope

Frequently asked questions