Outline the differences between the three different types of rock.

Igneous rocks

Igneous rocks are distinguishable by the fact that they are made up of crystals, which vary in size depending on where the rock was fomed.

Intrusive rocks consist of larger crystals - formed inside the earth by the cooling of liquid magma (lava inside the earth), e.g. in a magma chamber.  Examples include granites and gabbros.

Extrusive rocks have smaller crystals and form when the lava cools on the earth's surface e.g. in a volcanic eruption.  Examples include basalts and andesites.

Composition of both intrusive and extrusive rocks varies depending on the original composition of the magma.


Sedimentary rocks can form in rivers, lakes and oceans.

Form from particles of pre-existing rocks or clay material - sediments.

May contain shells of organisms that lived in the water column that can be preserved as fossils.

Examples include sandstones and mudstones.


Can be formed from sedimentary or igneous rocks.

The rock is subjected to high pressures and/or temperatures, resulting in the rock changing to remain stable.

May be deformed.

Very dense rocks.

Limestone metamorphoses to marble.


Laura S. GCSE Geography tutor

1 year ago

Answered by Laura, a GCSE Geography tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist


Jacob M. A Level Geography tutor, GCSE Geography tutor, GCSE Maths tu...
View profile
£18 /hr

Jacob M.

Degree: History (Bachelors) - Manchester University

Subjects offered: Geography, Maths+ 1 more


“Tutoring experience I have gained three years tutoring experience with five seperate students of different ages and capabilities on a one-to-one basis. The subjects I have tutored include Maths, Biology, Physics and Chemistry at GCSE ...”

Andrea P. GCSE Chemistry tutor, A Level Geography tutor, GCSE Biology...
View profile
£20 /hr

Andrea P.

Degree: Geography (Bachelors) - Durham University

Subjects offered: Geography, Chemistry+ 1 more


“About me:I am an undergraduate student studying geography at Durham University. I have a real passion for my subject as well as knowledge in general. That was one of the reasons I choose to study geography since, due to its broad foc...”

Sian S. GCSE Biology tutor, A Level Geology tutor, GCSE Geology tutor...
View profile
£18 /hr

Sian S.

Degree: Geology BSc (Bachelors) - Durham University

Subjects offered: Geography, Geology+ 1 more


“About Me?? I am a second year Geology undergraduate at Durham University looking to tutor Geology and Geography at GCSE and A level as well as Biology at GCSE. I am very passionate about my degree and love to help teach and pass knowl...”

MyTutor guarantee

About the author

Laura S. GCSE Geography tutor
View profile
£18 /hr

Laura S.

Degree: Geology (Bachelors) - Durham University

Subjects offered: Geography


“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

You may also like...

Posts by Laura

Outline the differences between the three different types of rock.

Why do volcanoes and earthquakes occur at destructive plate margins?

Other GCSE Geography questions

Why do volcanoes and earthquakes occur at destructive plate margins?

What features can be found at the mouth of a river?

What is an ecosystem?

How is a waterfall formed in a river?

View GCSE Geography tutors


We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss