TYPES OF ROCKS

What is a Rock?
A rock is a combination of one or more minerals or organic matter.

THE ROCKS

• Igneous Rocks
• Metamorphic Rocks
• Sedimentary Rocks

Igneous Rocks
Igneous rocks are rocks that form when hot, liquid magma cools into a solid.

INTRUSIVE IGNEOUS ROCKS

• Intrusive igneous rocks form by intruding surrounding rocks below Earth's surface.
• Example ; Diorite

EXTRUSIVE IGNEOUS ROCKS

• Extrusive rocks form when lava erupts, or extrudes onto Earth's surface.
• Example ; Basalt

Sedimentary Rocks
Sedimentary rocks form by weathering, erosion, deposition, burial, and cementation.

CLASTIC

• Clastic sedimentary rocks form when sediments are buried, compacted and cemented together by Calcite or Quartz.
• Example : Breccia

CHEMICAL

• Chemical sedimentary rocks form when water, usually seawater, evaporates.
• Example ; Halite

ORGANIC

• Organic sedimentary rocks form from the remains or fossils, of once-living plants and animals.
• Example ; Coquina

Metamorphic Rocks
Metamorphic rocks form when a rock is exposed to high temperature and pressure.

FOLIATED

• Foliated metamorphic rocks form when pressure causes the mineral grains in a rock to realign to form parallel bands.
• Example ; Phyllite

NONFOLIATED

• Nonfoliated rocks form when the grains in the mineral are not aligned in planes or bands.
• Example ; Quartzite