0812 Operation of gravel and sand pits and mining of clay and kaolin

08.12.1 Gravel and sand
08.12.11 Silica sands and quartz sands
08.12.12 Other natural sands
This subcategory also includes:
- coloured natural sands
This subcategory excludes:
- silica sands and quartz sands, see 08.12.11
08.12.13 Pebbles and gravel
08.12.14 Mixtures of slag and similar industrial waste products, whether or not incorporating pebbles, gravel, shingle and flint for construction use
08.12.2 Clay and kaolin
08.12.21 Kaolin and other kaolinic clay
08.12.22 Other clay, andalusite, kyanite and sillimanite; mullite; chamotte or dinas earths