Minerals in Construction: From Foundation to Roof

Minerals in Everyday Life 5 min read

## Building With Minerals

Every building is constructed primarily from minerals. Concrete, steel, glass, brick, plaster, and insulation are all mineral products. Understanding these connections reveals how mineralogy shapes the built environment.

## Foundation and Structure

### Concrete (World's Most Used Material)

| Component | Mineral Source | Formula | Role |
|-----------|---------------|---------|------|
| Portland cement | Calcite (CaCO₃) + clay | Various | Calcium silicate binder |
| Aggregate | Quartz gravel (SiO₂) | SiO₂ | 60–75% of concrete volume |
| Water | — | H₂O | Hydration reaction |
| Gypsum | Gypsum (CaSO₄·2H₂O) | CaSO₄·2H₂O | Controls cement setting time |

Global concrete production: ~4.4 billion tonnes/year, requiring ~3.5 billion tonnes of aggregate.

### Steel

| Mineral | Formula | Mohs | Role in Steel |
|---------|---------|------|---------------|
| Hematite | Fe₂O₃ | 5–6.5 | Primary iron ore |
| Magnetite | Fe₃O₄ | 5.5–6.5 | High-grade iron ore |
| Chromite | FeCr₂O₄ | 5.5 | Stainless steel alloy |
| Pyrolusite | MnO₂ | 2–6.5 | Steel strengthening |
| Molybdenite | MoS₂ | 1–1.5 | High-temperature steel |

## Walls and Insulation

### Brick and Ceramics

Bricks are made from clay minerals (kaolinite, illite, smectite) fired at 900–1100°C. The red color comes from iron oxide (hematite) in the clay.

### Plaster and Drywall

Gypsum (CaSO₄·2H₂O, Mohs 2) is the basis of plaster of Paris and drywall (gypsum board). When heated to 150°C, gypsum loses water to form hemihydrate, which resets when water is added.

### Insulation

| Material | Mineral Source | Properties |
|----------|---------------|------------|
| Fiberglass | Quartz sand + soda ash | Thermal, fire-resistant |
| Mineral wool | Basalt or slag | Thermal, acoustic |
| Perlite | Volcanic glass (obsidian) | Lightweight fill |
| Vermiculite | Hydrated phyllosilicate | Expands when heated |

## Windows and Glass

| Ingredient | Mineral Source | % of Glass |
|-----------|---------------|------------|
| Silica sand | Quartz (SiO₂) | 70–75% |
| Soda ash | Trona (Na₃(CO₃)(HCO₃)·2H₂O) | 12–16% |
| Limestone | Calcite (CaCO₃) | 8–12% |
| Dolomite | Dolomite (CaMg(CO₃)₂) | 1–4% |

## Roofing

- **Clay tiles**: Kaolinite fired at high temperature
- **Slate**: Metamorphosed shale (muscovite, quartz, chlorite)
- **Asphalt shingles**: Petroleum + limestone granules

## The Mineral Bill of Materials

A typical 2,000 sq ft house requires approximately:

- 100 tonnes of aggregate (quartz, limestone)
- 30 tonnes of cement (from calcite/clay)
- 2 tonnes of steel (from hematite)
- 0.5 tonnes of gypsum (drywall)
- 0.3 tonnes of glass (from quartz sand)