This document specifies a basic procedure for the identification of the petrographic type of natural aggregates. Precise petrographic identification, of technical mineralogy and petrography for civil engineering or specific end uses, 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 engineering and aware of the composition of the deposit, has sufficient skills to sample and name the rock.
NOTE 2 – For precise petrographic identification, a non-exhaustive list of reference literature is given in the Bibliography.
This document covers only natural aggregates. It is used to describe massive rocks and unconsolidated rocks.
Annex A provides guidance on the petrographic nomenclature by giving definitions of simple petrographic terms applicable to rock types used for aggregates.