“Types of Rocks”

Igneous Rocks

• Igneous rocks are formed when hot liquid magma cools down and becomes solid. It’s the most common type of rock found on Earth.

• The term igneous comes from the Latin word ignis, which means ‘come from fire.’ As the origin of these rocks is from scorching magma, they are called igneous rocks.

Sedimentary Rocks

• When deposits of sediments are compressed together, they form sedimentary rocks.

• Water, erosion, and weathering break down rocks and minerals into tiny sediments, which over time are deposited in sedimentary basins.

• These sediments are compressed under pressure and form sedimentary rocks. The example includes sandstone and limestone.

• Sedimentary rocks often include layers, also known as strata. Therefore sedimentary rocks are also called stratified rocks.

Metamorphic Rocks

• Metamorphic Rocks form when one rock changes due to heat, temperature, and pressure and transforms into another rock. The process is called ‘metamorphism,’ which simply denotes change from one thing to another.

• Metamorphic rocks involve specific conditions of high pressure and temperature, often found deep inside Earth. Moreover, the rock undergoing metamorphosis should not melt, or it will become magma, not metamorphic rock.

Depending upon the process involved, metamorphic rocks can be of two types;

• Non-foliated metamorphic rocks

• Foliated metamorphic rocks

Foliation is a process when rocks consist of consecutive thin layers. Foliation comes from the Latin word folium, which means ‘leaf.’