Grits are mainly produced in quarries. Explosives are used to create a mountain face. The base material is separated via a pre-sieve (0-70mm) in a touverant (70-500mm) which can easily be broken into several sizes which are suitable for, among other things, waterway and road construction, the concrete industry and garden and landscape design.
The pre-sieved material is also used as a foundational material in road construction.
Classifications of the various grades include:
- Crushed sand 0-2mm
- Foundation materials 0-31,5 en 4-31,5mm
- Grits 1-3, 2-5, 5-8, 8-11, 11-16, 16-22mm
- Crushed stone 30-63 en 45-125mm
- Quarry stone for gabions 80-150 en 80-200mm
- Other quarry stone 100-400, 150-300 en 200-500mm
- Rubble (waterway construction) 5-40kg, 10-60kg and heavier sortings
Glacial erratics, which are large decorative rocks that are either too large to be broken or so attractive that they are sold separately. Glacial erratics of 100kg to 30 tonnes are available.