This Part of BS 812 describes a general method for the examination of samples of coarse or fine aggregates to determine petrographic composition and to assist in the assessment of those aggregates for potential suitability for the intended use. The results relate only to the sample received at the laboratory and not necessarily to the deposit from which the samples are derived. The method is applicable to the determination of the proportion of any recognizable mineral or rock type, irrespective of the amount of such material, in the sample.

The major application of the method described is in the examination and assessment of processed aggregates.