Quartz is the mineral silicon dioxide, chemically SiO2, and after the feldspars the most common mineral in the earth’s crust. It is hard, exceptionally stable chemically and practically insoluble in water. On the Mohs scale quartz has a hardness of 7, so it scratches glass but is not scratched by glass.
For construction, quartz matters mainly as the principal constituent of sand and gravel: by far the greater part of the sand used in concrete and mortar consists of quartz grains.
Where quartz appears in construction
- Concrete and mortar — as aggregate in sand and gravel; the durability of concrete depends partly on the stability of this quartz
- Glass — glass is melted from quartz sand with soda and lime
- Composite worktops — quartz grains bound with resin; hard and stain resistant, but not UV stable for external use
- Natural stone — granite, sandstone and quartzite owe their hardness largely to their quartz content
- Abrasives and blasting grit — because of the hardness, though quartz blasting grit is being replaced on health grounds
Silica dust: take the health risk seriously
Cutting, drilling, routing, grinding and breaking out concrete, brick, natural stone, tiles and cement-bound boards releases respirable crystalline silica. Prolonged exposure can cause silicosis and lung cancer, and workplace exposure limits and control measures apply.
Always work like this:
- Control at source first — cut and grind wet, or use tools with on-tool extraction connected to the machine
- Class M or H extraction — an ordinary site vacuum is not enough; use a vacuum with the correct filter class
- Respiratory protection — for the residual risk, at least an FFP3 mask fitted closely to the face
- Screen and ventilate — separate the work area and ventilate it; do not let others work in the dust cloud
- Clean without raising dust — do not dry sweep or blow down, but vacuum
Related terms
- Quartzite
- Sand
- Concrete
- Natural stone
- Mortar
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.