L4 ROCKS AND MINERALS

Rocks

- Formed from a natural aggregation of one or more minerals and other substances

- Building blocks of the Earth's lithosphere

- Poor conductors of heat

IGNEOUS ROCKS

- Molten rocks cooled and hardened

- The time it takes for the magma to cool determines the texture of this rock

INTRUSIVE IGNEOUS ROCKS

- Magma inside the Earth

- Large crystals

EX: Granite

EXTRUSIVE IGNEOUS ROCKS

- Existed lava on top of the Earth's crust

- Small or no crystal

EX: Basalt, Obsidian, Pumice

SEDIMENTARY ROCKS

- Formed on the Earth's surface from deposited, compacted, and cemented sediments (pieces of rock, minerals, and organic matter)

- Formed through weathering and erosion

LITHIFICATION

Unconsolidated materials are solidified through

CLASTIC

Broken fragments of OTHER rocks

CHEMICAL

Minerals precipitate from water (ex., limestone, rock salt, stalactite)

ORGANIC (BIOLOGICAL)

Formed from the remains of plants/animals

METAMORPHIC ROCKS

Formed when existing rocks are changed by heat, pressure, or chemical processes without melting

PROTOLITH

Previous rocks before the process of metamorphism

FOLIATED

Have bands or layers (ex., Slate, Schist, Gneiss)

NON-FOLIATED

No bands, uniform texture (ex., Mable, Quartzite)

MINERALS

- Naturally occurring inorganic solids made of one or more elements, with a definite chemical composition and an orderly atomic structure.

CLEAVAGE

The tendency of a mineral to break along one or more planes

HARDNESS

- The resistance of a mineral to scratching is commonly tested through the MOHS HARDNESS SCALE.

MOHS HARDNESS SCALE

SOFTER: more likely to break down

HARDER: More likely to survive

COLOR

Perceived WAVELENGTHS of light bounced off from the material and detected by our eyes

STREAK

The mark formed when a mineral scratches across an unglazed surface, which shows different colors

LUSTER

The BEHAVIOR of light as it is reflected by the surface of a mineral