Under 622 is classed information about the exploiting of ores and other mineral deposits (preliminary surveys, extraction, mineral dressing etc.). Properties, occurrence etc. from a geological point of view are classed under 55.
Non-metallic minerals as raw materials for the chemical industry are classed under 66, especially 662 (explosives
and fuels) and 666 (glass, ceramics, concrete).
Extraction and refining of metals from ores are dealt with under 669.
The uses of mineral products, metallic and non-metallic, are considered under the appropriate subjects, e.g. for road construction 625.7/.8 and for building materials 691.