Rocks and Their Importance

Fundamental components of the Earth, formed from aggregates of minerals.
Source of fuel:
- Petroleum products derived from sedimentary rocks include oil, coal, and natural gas.
Used as construction materials:
- Granite and sandstone are quarried for infrastructure projects such as roads, bridges, and buildings.
Tourist attractions:
- Natural landmarks like the Grand Canyon National Park draw visitors due to their unique rock formations.
Provide food and nutrients:
- Rock salts (sodium chloride) sourced from sedimentary rocks contribute to human diets.
Essential for soil formation:
- Physical and chemical weathering of rocks creates soil, vital for agriculture and food production.

Igneous Rocks:
- Formed from the solidification of magma, containing various mineral deposits.
- Typically do not react to acids, with mineral deposits presenting in patchy forms.
- Subtypes:
  - Intrusive Igneous Rocks (Plutonic): Formed within the Earth's crust, characterized by slow cooling and coarse texture.
  - Extrusive Igneous Rocks (Volcanic): Formed at or near the Earth’s surface, resulting from rapid cooling, exhibiting fine or glassy texture.
Sedimentary Rocks:
- Composed of lithified sediments or remains of living organisms.
- Formed through a series of processes including weathering, erosion, deposition, burial, compaction, and cementation.
- Occupy about 75% of the Earth's crust, typically layered (strata).
Metamorphic Rocks:
- Result from the transformation of existing rocks under high heat and pressure (metamorphism).
- May exhibit foliation (banding) and can vary in color from light to dark.

Naturally occurring inorganic substances with specific chemical compositions and physical properties.
Serve as components of rocks and crucial materials for various industries.

Rocks and minerals mined for processing into everyday products.
Ore: A deposit that is economically viable for extraction.
Extraction methods:
- Surface Mining: Utilized when ore is accessible near the Earth's surface, employs open-pit, quarry, or strip mining.
- Subsurface Mining: Required for deeper ore deposits, involves digging horizontal or angled tunnels; commonly extracts iron, coal, and salt.

Groundwater and surface water contamination harming water quality essential for communities.
Instability from collapsed tunnels posing safety risks to miners.
Landscape destruction associated with methods like strip or pit mining, affecting ecosystems.
Air pollution resulting from mineral extraction processes and waste materials (slag).